Sorry if my english is not perfect (after all its not among the two official languages we speak here. And still there's another language in my home additionally), but i would still guess, it should be pretty obvious: paying too much to your top players. So top-loaded cap structure is maybe better term?
The trend to spend extra millions to front/top players is obviously not resulting cups. In the end, what ypu can gain by having topmplauer instead of very good, is not enough to compensate the loss of having to replace good middle 6 player by an average rookie.
I know, many if not most thi k vice versa but results are are showing different story.