Not really. Because it doesn't matter if you choose to support an alternative EV maker. If you actively campaign against Tesla you are hurting EV sales. There are Tesla's built today that should be purchased instead of ICE vehicle. Anything you do that stops someone else (even if you're not going to buy them yourself) is actively hurting the fight against global warming.
The only reason you would hurt the fight against global warming, is that you don't think it's as important as your reason for hating Musk. And that's a form of denialism. You're denying (if only to yourself) that climate change is going to cause death and destruction.
There is nothing internally inconsistent about weighing the pros and cons and deciding what measures are and aren't worth the benefit considering the drawbacks.
Maybe you should think about it a while longer. Or find a friend who's better at coming up with ideas to help.
There are about a zillion other explanations. Maybe they think that "ANY messaging that encourages EVs dissuades the public from going public transport" and that's harmful. Maybe they see other EV makers as preferable to Tesla. Maybe they care deeply about global warming but just as you said, are letting their anger get in the way of that goal. Maybe they see the immediate harms of Musk's policies as a more urgent problem than climate change.
There's a tremendous leap between "Not supporting Tesla because of Musk" and climate denialism.