He's mainly involved in technologies with the potential to transform humanity: making it multi-planet, reducing dependency on oil, expanding intelligence, etc. I don't know if his technical acumen on those fronts is good or not, but you can't honestly look at all these efforts and say "that's a moron".

Twitter is kind of an irrelevant side-project due to his increasing involvement in politics, where he's clearly on the stupid side of things. Judging his intelligence on that alone is a bit ridiculous.

Also you're assuming he's imploding Twitter out of incompetence and not on purpose. Remember he can afford to do it, he's a troll and quite childish. I find it much more likely that he's doing it for the tax benefit, out of spite for having been forced to buy it, or even for the lulz.

And to be frank, who are we to judge his intelligence after all his achievements? You think luck alone can produce SpaceX and Tesla, both incredibly innovative and disruptive companies? What exactly have you achieved that you feel qualified to pronounce him a moron? He may be a horrible person, but a moron?