In keeping with the ‘peace-rock on’ philosophy of the 60s (not that peace is not a wonderful thing) the bishops (God bless them) made a pastoral decision that people be
strongly encouraged to substitute a penitential practice. This went well in line with the idea that people should be freely choosing to do good as opposed to having the
appearance of being
coerced into doing good.
Again there is nothing intrinsically wrong with the idea, especially for those who are relatively spiritually advanced.
Unfortunately, the altruists of the 60s have pretty much gone on to be the hedonists of the 70s, the power brokers of the 80s, the comfortably well to do of the 90s, and the ‘I’ll do it my way’ neo-Sinatras of the 00s.

Raising their children equally unfortunately to be the skeptic, new-ager, radical eco-spouting material kids.
(NB: This does not apply to every person or to every Catholic, of course)
Thankfully the fasting/abstinence rule **is ** a discipline (as many like to point out, as being ‘subject to change’).
IMO, it is time for it to be changed back to the universal norm. We Americans were not ready for the challenge, and I’m not personally blaming people–after all, considering the great showing America had put up as compared even to other excellent societies when it came to religious observances, one cannot really say the bishops did not have a strong indication that, if anybody could live up to the challenge of ‘doing good without force’ it would be Americans.
But we couldn’t. We didn’t. We made things worse because we are restless and disobedient. We didn’t realize perhaps just how restless and disobedient we were.
So a lot of us are now in the position of having been ‘forced’ into humility. Look at the chance we got–and look how we blew it. We are no better than any other group; we are probably worse than many. . .
But there is no need for despair. Just as with ex smokers (as an example), those who have quit are more zealous against the evils of smoking–so too on that happy day when we once again have the universal norm those who will become ex “our way to observe what we want, when we want, even if it’s nothing at all” will very likely become more zealous in promoting the good of fast and abstinence.