That's because the quality of Tesla and SpaceX's products have nothing to do with Elon himself being an obnoxious ass. Steve Jobs was a horrible human, too, yet Apple is a going concern.
If I remember correctly, Steve Jobs did try to maintain non-offensive outward persona. At least from what I remember, the people who he was an ass to were mainly people physically near him: family, coworkers. Scaling that to whole social platform is rather different in scale.
