Fine. So be it.
Does it change the fact that there’s still more Diablo 3 fans today, then there are Diablo 2 fans, again, today?
The difference is orders of magnitude.
Even if Diablo 2 was, as you suggest it, bigger game for its time - that doesn’t matter anymore. What matters is that catering to Diablo 3 playerbase is much more profitable than catering to a dwindling number of Diablo 2 fans, most of whom grew adult, had family, and aren’t interested in gaming anymore.
If anything, your distaste for Diablo 3 only proves my point. Your individual opinion as a consumer doesn’t matter. It is still one of the most successful games of all times.
And what does your sudden aptitude for seeing future has to do with reality of this dicussion?
YOUR definition of good. Not quite the developer definition of good.
See, here lies an intrinsic problem to your opinion. You don’t see a larger picture.
YOUR definition of good is based on how well YOU like something.
But the DEVELOPER definition of good is based on how many OTHER PEOPLE likes something. Be they filthy casuals, hardcore fans of the series, neckbeards with bear-belly or housewives.
Developer still has his own tastes. But they discard them in favor of making a better game that more people can enjoy.