Disclaimer: USA perspective here, I know its less bullshit in many other parts of the world.

People who don't like PTO don't like it because:

It is implemented in a bullshit way that is often literally illegal...

And it is implemented by idiot/cheap managers who don't have enough actual staff hours to cover anyone being sick or taking PTO.

The bog standard norm for every kind of min wage tier job is that the manager will just unapprove your vacation that you accrued and scheduled weeks or months ago, and then oops, that also makes it so you haven't been accumulating more PTO because you hit your max and didn't use it in time.

Or just any manager that says you can only have a sick day, vacation, or any kind of emergency if you find a replacement for your shift.

That one is particularly amazing because... that is literally the manager's job, to do that, not yours.

But they just gaslight you into doing their job for them, for no extrs pay, of course.

But this kind of (again, often literally illegal) bullshit is so totally common and normalized amongst these shit ass jobs, that most workers don't even know how bullshit it is, and will rabidly attack and malign their coworkers instead of blaming their petty tyrant boss.

These people are basically, generally correct in identifying PTO as basically bullshit in these situations, but they're too overworked and uninformed to put together that... it could be organized/executed in a not bullshit way, and it's their boss's (or corporate's) fault that it isn't.

Shitass retail managers routinely pull this bullshit and enforce a culture of blame being on all your fellow workers, and will go out of their way to intentionally stoke interpersonal drama amongst coworkers... it is very, very rare to find a low level franchise manager or small business owner who does not do this.