Agreed. It's like saying that Path of Exile is a reskin of Diablo because they use a mouse. The biggest issue I see with Diablo Immortal is that it is releasing on a platform with a massive stigma among the gaming community. If the game was both PC and mobile I could see it being received better, but Blizzard completely miscalculated about how much hatred there is for mobile gaming amongst gamers, and for good reason.
If they can make the game actually good without all the bad stuff that mobile games tend to have like awful microtransactions and stuff, then Blizzard might make mobile gaming a little bit more respected. However, they frankly need to reconsider not making a PC version as well, since that is just incredibly stupid.