I think everyone needs to decide for themselves.
One thing that irritated me a little was it seemed in the '90s we had a lot of road racers in this country who seemed more than happy to point out that they weren't taking the sport too seriously, just having fun. What irked me was at the time these were some of out top runners.
I admit I envy someone who can work 40 plus hours a week at a real job and run 85 miles a week and go 2:13 for a marathon, but I'll admire the guys who are putting more into their running and laying it all on the line, even if they run slower.
Of course there comes a time when you have to be practical and decide if it makes sense. If your on your own with no family to support I guess you can live your life however you want but if you've stagnated for a long time you have to know when to call it quits. Running as your sole focus for 99% of national class runners will put you behind everyone else in the job market out there who have built up resumees over the years with things other than "training for the Olympics, two-time national team member, etc."
Can you do both, I guess it depends on what line of work you get into, but I don't think anyone has a shot in hell of cracking the world top-ten in any event unless running is number one and I don't think any employer will cut anyone a break to do this nor do I think they should.
Therefore, there probably shouldn't be any more or less people "going for it."