The service is more than the code base: it's who is offering it, who supports it.
Besides, I'd be shocked if that analogy is how the law works. Perhaps if you'd bought an individual license then sure, you could resell it with the brand name, just like the car. But wholesale is a completely different situation.
It depends on the legal jurisdiction but in the US you're allowed to use a competitor's brand name/trademark specifically to inform your customers. E.g. "acetaminophen, the stuff that's in Tylenol". You can also use the competitor's brand colors.
so if I create a website called other-Facebook.com that looks exactly like Facebook, I can even tell people I'm going to steal their time and information just like the real Facebook, and that's allowed?
Besides, I'd be shocked if that analogy is how the law works. Perhaps if you'd bought an individual license then sure, you could resell it with the brand name, just like the car. But wholesale is a completely different situation.