This entire thing sounds like another version of in a reductionist way, of just blaming what is popular. You don't like where the popular thing was headed, and so you blame it, because nobody else could craft something that speaks to your little snowflake sensibilities. Be it Call of Duty, Pop Music, or whatever else, the line of thinking always seems to be the same. Blame what is popular, for the competitions inadequacies. It's a childish hypothisis as it is ignorant and not well-thoughtout.
Everyone knew MMORPGs were destined for great things. Everyone always saw the potential. I played SWG which was the market leader before WoW. At its highest point it attained 450,000 subscribers, and was a massive investment for SOE and LucasArts, banking on its sandbox style gameplay. That game didn't fail because WoW became popular. That game failed because the developers failed at making their own game work on their own terms, so they doubled down and tried to make it a WoW clone.
Had it been some other game the result would have been the same. All EQ/WoW did was bringing some new streamlined gameplay to the tables that made it easier for non-gamers and non-MMORPGers to get into. If you look at objectively, UO, M59, AC and SWGs great things all come from the MMO technology- Not because they had great gameplay design with tight balanced mechanics, smooth combat systems, great UIs and so on. They were barren worlds, the games were hard to get into, they were stagnant, there was little room for casual gamers, and the games had uninspired world building, usually bad lore, poor controls, sluggish performance. WoW did a whole of a lot with its simplistic approach which makes it deserve its accolades. As a video game, taken out of a MMO context its just a much better crafted game. That came at the cost of some social MMO features, but like everything else there is a tradeoff.
For more than 10 years MMORPGs have gone in a direction that has little to do with WoW. Games have gone free-to-play, and many MMOs are embracing hybrid models. Lobby based MMOs, that take the persistence character building on the game servers of games like Warframe is extremely popular, and you see these new sub genres of sandbox and survival games with MMO features on Steam. And why not? MMOs were not known for their combat systems, their great stories or any of that sort. It was the technology of being able to connect a mass amount of people in a multiplayer verse that make the world feel more alive, and now you are seeing a transition of developers taking those technologies into other genres, regardless if its a shared universe in Star Citizen, a mountain range in Steep or whatever else.
The entire gaming genre is based on fads, like all of entertainment. You're mad about change because nothing has come out that suits your needs specifically. EVE is a great fucking game. And a game that has persisted over time. Planetside 2 is a great game. Warframe is a great game. Guild Wars 2 is a great game. Black Desert is a great game. And none of these games are anything like WoW. They bring other combat systems and other game philosophies to the mix.
And if you take of your nostalgia glasses and realize, that the first time you play something or experience something its a lot more amazing because its new and novel. Its not just going to create the same feeling the other times. People who started with DAOC say the same thing. People who started with WoW say the same thing. It's always the same honeymoon based story. The first thing that they specifically played and got really sucked into is amazing, and everything that followed couldn't hold up. That's just another way of being an old man yelling at what the kids like.