He pitched in a lot of cash at a do-or-die moment in Tesla's history.
He then served as the CEO and driving force through some extremely lean and tough years, including working like hell to raise capital (which isn't optional if you're making cars)
Would we have Tesla today without Musk? No. Would electric cars be ubiquitous if it was up to the likes of Ford, GM, Mercedes, Toyota to push the tech? No.
It is, of course, entirely OK to dislike him - but at least admit his contributions.