Why wouldn't I be serious? A significant number of people playing this game are present on Twitter and they're openly advertising that their primary use of the game isn't to actually play it but to mod and lewd it.
It's been a problem for a while, escalating in recent years. Even when I roleplayed in this game, there was always this sleazy portion of players trying to pressure people into engaging in ERP even if they declined. That portion of players has grown emboldened over time to the point where many threads have been made regarding the number of venue adverts filling up the party finder (some of which are outright adult in nature).
You could also look at the amount of players casually advertising their deepest, darkest fetishes in a carrd profile linked to their search info.
One thing that is consistent, however, is that whenever any of this is pointed out it is always downplayed.
Just the other day there was a thread here where someone was defending pedophiles. It's past time to stop pretending that this game doesn't have a growing number of genuinely unsettling players who aren't here for the actual game as intended but as a Second Life simulator.
Furthermore, where did I say the game is 'dying'? I doubt it'll die, much in the same way as World of Warcraft isn't going to die. It doesn't mean the game can't go in a completely different direction and screw over the original target audience, though.