I flew Ryanair for the umpteenth time yesterday. I have never had a problem of any significance with the airline, except for how long it took to refund the payment for a cancelled booking. This compares well with some other airlines I've used - most of which I've flown fewer times than Ryanair - and includes a small number, such as Iberia, which I will never use again.
Whilst rudeness from customer service staff is always unacceptable (although understandable in some circumstances), too many people today believe that the "customer is always right" attitude gives them the power to run shipshod over an airline's regulations - e.g., over baggage weight or cabin baggage dimensions.
[I'll never forget boarding a KLMuk BAe 146 at Amsterdam early one morning and having to put up with the special pleading from "someone important" that he was unaware that his bag was too big for the cabin and that this had been no problem on his first leg, into AMS, on KLM. (I, too, had just flown the Atlantic on KLM and was perfectly aware that the "change of gauge" meant that what could be taken on a 747 might be too big for the 146.) The cabin attendant had the patience of a saint but I bet the passenger later complained about how he was treated.]
It's simple. Read the conditions of the contract (freely entered into!) and stick to them. It's not rocket science! Claiming that it's unreasonable to be expected to read the "small print" is pure laziness (save in cases where passengers are functionally illiterate).