I think a lot of the 'attitude' you see is when people complain publicly about things that are entirely their fault. e.g. "They charged me to print my boarding pass, I didn't know I had to do it digitally" - probably because you ignored the multiple emails they sent you over the last month warning you. Or "my bag was fine on the way over and now they say it's too big" - you never bothered to check the size and got lucky on the way over. All of these types of rules have been in place for decades now and it's always the seem people holding everyone up because they think the rules don't apply to them.
The worst experience I've had with booking _ever_ was recently and it wasn't Ryanair. Whizzair rejected my cards (all of them) and then said the only option was a bank transfer. No fucking way am I doing that. Then my partner tried on her app. Every time she went from the payment screen to her banking app to approve the transaction, she'd go back and the entire app had lost state.