Good marketing for who? It's not like the cars themselves suddenly got worse. I think most people don't engage in victim blaming when someone or some group are targeted by domestic terrorists, which is definitionally what is happening (Oxford Languages: "the unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims").
The people who should worry about the marketing problem here are the Democrats. They're directly funding this violence and vandalism via their NGO network, don't seem to be condemning it and it's their inverted rhetoric claiming Republicans are Nazis that has now created a left-wing street army physically attacking anyone who supports the opposition: exactly the tactics used in the Weimar Republic. Irony is surely dead.
Also, a lot of the people getting vandalized or pressured to inconveniently sell their car at a loss are Democrats themselves, many of whom will certainly be wondering why they're supporting the team that would directly attack innocent people in such horrible ways.
It's unlikely Musk would care even if Tesla really suffered. His biographies make it clear enough. Getting rich has never been what motivated him, and he owns private companies that are basically terrorism-proof. They spin off enough money to sustain his often rather spartan lifestyle in any case. All these attacks will do is build sympathy for him, for the right, and radicalize them still further.