Let me guess - you have read about running in the 1970s but never lived it. Having started running in 1968, daily running in 1972, and having logged about 78,000 lifetime miles, many of them alongside sub-9:00 HS 2-milers, sub-1:45 800m runners, sub-3:55 milers and 2:10 marathoners, as well as the recreational crowd and every competitive level in between, I'll help get you up to speed on the way things really were during the 1970s and the 1980s. Heck, I'll even throw in a pitch about the 1990s.
First of all, the "general" running population of the 1970s consisted of serious competitive runners of the original "running boom" (which was no doubt influenced heavily by Dr. Ken Cooper's "Aerobics" in 1968 and fueled by Frank Shorter's gold medal in the 1972 Munich marathon). There were also a few of the fitness joggers that comprise the lion's share of today's "participation boom." I never met a single person involved with competitive running at the time who did not know about Lydiard, his methods, his Olympic athletes, and his influence in the sport from New Zealand to Finland and to the U.S. Even most of the joggers knew about him, just as today's joggers know about Runner's World's recommendations on the most comfortable fanny packs and tastiest post-race snacks. Dr. Cooper, Shorter, Jim Ryun and (later) Bill Rodgers were the "household" running names in America at the time, but the general running population knew all about Lydiard, and virtually all the literature of the era promoted long periods of relaxed base training with weekly long runs, and what was at the time called "high steady state" running (which would now be called "threshold" running or AT or tempo). People ran the roads as often as they ran X-C and track. Most low-key local road races were vastly more competitive than they are today, and national-class or world-class runners would sometimes show up unannounced for these small races in the bigger cities and would occasionally have their hands full with a local guy or two. Running was that competitive among the masses then. I know first hand because I was in many such dinky city races with national-class guys (and I once got outsprinted for the win in the last 200m of a half marathon by none other than Tony Sandoval ... when he had one of his worst days!). Even high schoolers and college runners did these road races regularly. High school performances were at an all-time high in 1976. The U.S. won individual and team titles at the world junior X-C championships from 1974-1977 and went 1-2 (Hulst and Hunt) in 1976. College runners were competing against world record holders and Olympians in NCAA meets, some were Olympians themselves and many went on to world-class status.
Enter the 1980s. While the elite runners (who had grown up during the 1970s running boom and understood how to train) were still running sub-28:00 for 10,000m (Nenow, Bickford, Eyestone, Sandoval, etc.) and scads of 2:10-2:15 marathons (and a few 2:08-2:09 times on p-t-p courses), the high school crowd (beginning circa 1979) had moved toward a "faster must be better" mantra. Coe obviously did not start this, but his assertions that "modern middle distance running is about speed" (another direct quote), as well as the other quotes mentioned above, fed a virtual cult of misuderstanding followers who praised the Emporer's new clothes of high intensity. The biggest problem was the non-runners in the white lab coats determining (in true "forget what we told you several years ago; this time we've really got it right" fashion) that max VO2 could be improved to its ceiling by running 35-40 miles per week. The next generation of runners, already overestimating the importance of max VO2 in predicting performance, was happy to hear that they could be back at the arcade playing Asteroids and Pac-Man after a 30-minute track workout. Virtually every piece of literature of the mid-1980s announced that the trend in training was toward lower mileage and higher intensity. Performances on the depth charts plummeted, first among the high school ranks and then among U.S. elites. Runners who had burned out from high intensity and mediocre performances in youth had little reason to stay in the sport, and the elite ranks thinned.
Then came the 1990s. This decade saw the explosion of growth hormone and recombinant erythropoietin. East Africans began to dominate the sport (not sure if there's any connection to the drugs). Dieter Baumann beat a horde of them in Barcelona to win the 5,000m gold medal, but the long track races would soon become Ethiopia vs. Kenya (and, later, Kenyan defectors), while the middle distances saw more North Africans and a smattering of Euros challenging the mighty Kenyans. Kenyans also began making a laughingstock of American road races. Americans struggled mightily. Steve Spence's WC bronze in the marathon briefly sustained hopes for a comeback, as did Mark Plaatjes (via S. Africa) winning the 1993 WC gold for the U.S. But by the middle of the decade, only Todd Williams and Bob Kennedy were mixing it up with the world's best on the track and in X-C. Admittedly, Kennedy was a low mileage runner in high school and only a moderate mileage runner in college, but he blossomed when he moved to the 100-140 mpw range, running 12:58 twice the following year and briefly leading the Olympic final in Atlanta. Williams also logged up to 120 mpw when he was gamely gutting it out with the Africans in 1992-1995, while Jerry Lawson and David Morris were doing likewise when they popped 2:09 marathon ARs. The only world ranked or world listed male Americans of the 1990s were those who did what? That's right - the same training mileage that their predecessors did 10-20 years earlier to become world class themselves. But in the 1970s and early 1980s, there were many more of them.
See above. You obviously were not involved with the sport in America during both decades. I was involved alongside the runners themselves at every level from junior high school to elite, and everyone else who was likewise involved will give you the same answer. Lower mileage during the mid-1980s and beyond was the norm and was the sole reason for the decline in performances. This is absolutely unarguable to anyone who was a serious runner during both decades.
"Think" is the key word there. The ideology is unquestionably one favoring intensity. While the exclusion of volume is not specifically encouraged, it is stated very explicitly that such volume is not required to produce maximum performances. This line of thinking is simply DFW.
Re-read those quotes and explain how they can possibly be taken "out of context." What "context"? Again, "It eradicates the need for high mileage" and "... long slow distance makes long slow runners." Isolated, maybe. But this is what people heard or read. No grey areas there. No room for interpretation. The message is the context and it could not possibly be any more straightforward.