People hate Reforged because it's crap, objectively speaking it's shit, it's useless. It breaks everywhere, the graphics are generic mobile game graphics and Blizzard hasn't stopped lying and scamming the STUPID PEOPLE who keep swallowing and buying all the crap they release.
That's why people hate Reforged and well, the fact that there are too many people playing it... I don't know what concept of "alot of people playing it" you have, but the game is completely dead, the four crazy people always play it and that's it. In fact, some of the long-time players have ended up leaving it.
Regards.