There isn't even a need to discuss the intent of the salute; just look at who he donated to and who he supported as candidates. The problem is that buyers who want EVs are much, much more likely to align with the opposite ideology.
I am not making a judgement here at all and I'm making zero comments on Musk's ideology or character, only that he made a poor branding decision by supporting a voting base and politicians that to not represent the folks most likely to buy a Tesla.
You don't need to argue the intent of the salute; you can just see which candidates he supported and donated to.
(It's fine to debate policy on things like incentives, but that is at least part of the reason why we see China making big leaps here because the government has aligned the incentives with buyers and manufacturers to make electrification the default)