I'm not saying you're wrong, but I perceive it very differently. I think the game itself is extremely welcoming and friendly to anyone. It does not discriminate when it comes to ability, motivation etc. If content is too hard for you, they'll make it easier for you one way or another. So in essence, the game itself promotes a relaxed mindset, personally I find that refreshing. If you want a real challenge, you have to go look for it and find likeminded people, which imo is an elegant solution.
Not everyone can improve. Not everyone wants to improve. Some are new. Some have returned after a long break. Some people will burn all that motivation on their job already and just want to log on and not get more hassle thrown their way. Some are a bit older and don't have the best reflexes (anymore). Some are tired cause they have small children, a demanding job, a migraine. Some suffer from anxiety, depression, you name it, and are not feeling at their best. Applying more pressure isn't necessarily going to help, isn't always going to magically improve their performance. They may be perfectly comfortable with where they are at. And the game respects this, very much. So if players defend the right to play at your comfort level, whether it's for themselves or others, I simply see them respecting the spirit of the game.
Expecting, demanding, pushing, complaining when players are not playing to the full potential of a class or role seems off to me. You can offer help, you can respectfully nudge once or twice but you can't and shouldn't make people play the way you want them to if that's uncomfortable to them. Which "You're not paying my sub" is pretty much the logical response to because it's so true. Instead of being frustrated with or exasperated about that attitude, understand what triggers it and respect the limitations of others. Everyone has them, and there's no rule book that says we have to overcome all of them. When someone logs on to relax a bit, that may just not be the right time to expect that haha.