That's not a good analogy. A better one would be if the Kleenex people reached a deal for a second company to market its tissues as "Cleenecs". My understanding is that that would make it easier for a third company to come along and use "KKleenXXX" -- they could argue that the word was becoming a generic term. (Trademarks can be lost if they wind up being used generically. Examples include "aspirin" and "elevator".)

But fine, let's leave the legal questions aside since neither of us is an expert.

I don't concur with your assessment of the ethicalities of the situation. Who's Here was up first and Hamachek knew about it. He could have picked a clearly different name, but did not.