Let me know the site for the Chinese guy's blog--let's see how I can understand it... (just kidding!)
It is because anaerobic training feels so good that you just can't stop it. Another silly joke. I'm at the point where I'm not running as much or as hard. But if I choose to, I can probably get up and get to the point where I can run for 2-hours and feel good within 2 or 3 weeks. This is what Lydiard meant by saying "once you'd developed your aerobic capacity, you don't lose it." In other words, in your case for example, you have built such a good solid aerobic base that you can always fall back on to if you choose to. In a large part, it is the development of capillaries. Once developed, even though they might shut down for a while, it would be relatively easy to open up again. Anaerobic capacity is different. It is more a chemical matter. It is to develop buffer against large lactic acid build-up in your blood stream. In other words, you take something like 3 to 5 weeks to develop this chemical buffer and, if you don't continue, you lose that ability. As has been debated here as well as other threads (or other message board???), performing anaerobic training can affect your aerobic capacity adversely so you don't want to keep doing it; yet, if you stop doing it completely too early (before main competitions begin), you'll lose that ability. This is why Lydiard prescribed what he called "sharpeners" or, unlike some people think (of Lydiard being so arregant), "Igloi training". This way, you are still stimulating this chemical reaction in your body but not in the same valume as earlier.
Perhaps to phrase it differently, "once you start doing anaerobic training, you need to keep doing it in order to maintain the same level of anaerobic developmen." You CAN stop doing it, but then what's the point of coordinating all the schedule? This is the problem with some program; they start doing anerobic training way too early in the season; but neglect it when the competitions near. This is the advantage of the Lydiard program--you know what to do when.