Sure it's their car and they can do whatever they want with it, but consumers are losing choices - which is what anti-monopoly rules are for. Say, Michelin or Pirelli tires are strictly better but Tesla doing this harms consumer choice and that's why it is bad.
Imagine if this were extended to Tesla branded chargers. Or Tesla branded paint. It's your damn car so you should be allowed to do whatever you want with it.
