He was, but it doesn't change the fact that his inventions effectively revolutionized society. Tesla gave us alternating current, radio, radar, so much of the tech and principles that led to wireless communication and transistors. Tesla was a eugenicist, which makes him a colossal asshole, but again, he still deserves better than to be associated with Elon Musk.

Musk didn't even found Tesla Motors. He bought the company from the founders (aka the guys who actually did the engineering and cool stuff) and with the purchase, bought the right to call himself a founder. The engineers who actually founded the company, Martin Eberhard and Marc Tarpenning, are contractually forbidden from referring to themselves as the founders.

tl;dr, Musk is a rich asshole basically cosplaying as an entrepreneur, and everyone bought into it.