Because sex is overrated, and it's pushed to the ridiculous extreme as a virtue that no other natural process seems to get.
You can't eat? You die.
You can't sleep? You die.
You can't breathe? You die.
You can't eliminate? You die.
You can't get laid? You'll live.
You can't be 'celibate' with any of these other processes save for sex and hope to come out of the experience alive. No man or woman has ever died from not getting laid, yet people push and pressure other people into it, even when it can be detrimental to that person. And before people say 'Oh but we need sex to continue as a species!' Well, it's one thing if the person is ready for it and wants to have a baby, not when they get pressured into it through societal pressure that they aren't really an 'adult' until they had it, even as that makes no biological sense.
And as for sex workers? How freeing and good is it when you use your own horniness to justify using that woman/man as a commodity? Then you ought to then just cut off your own wanker, because it's just a useless and troublesome organ that you don't need if it leads you to act less then civilized. It's not progressive if you have to literally use someone just to get your rocks off, even if you want to claim to abstain is just a remnant of some older part of the culture that you consider 'prudish.'
_________________
Crispy Pickles!!