Why do we equate difficulty with quality and vice versa

Now look, I've seen on multiple times in media that if a boss is easy it's bad and hard equals good, most of the time. Due note I've played bloodborne, sekiro, and dark souls 3 only so I'm looking from those examples(but I'll use Elden ring as an example). Look at a boss like Darkeater Midir, he is hard and everybody loves him for it. But why though, to me his a pretty solid boss that does high damage and is just a damage sponge. Let's look at ab easy boss, crystal sage. Everybody clowns on him and for the most part it's justified, but to say his a horrible boss to me atleast is a stretch. Let's look at Elden Ring, Radahan or whatever the final boss of SOTE is, has caused controversy by being too hard or unfair. Where do we draw the line? I personally say not every hard boss is amazing, and not every easy boss is bad. Example Gael. Gael isn't easy by any means but his difficulty isn't why most people like him, but everything that supports it. Look at oceiros, that rat bastard is difficult but not fun at all. I know this is a cold to lukewarm take but what do you guys say about it. Also why do people get do butt hurt when you say a specific boss is easy