> Also, the aggressively protect your trademarks or lose them thing is a myth.
It's not. For example, Bayuer lost their trademark for aspirin due to genericization.[0]
For more context about copyright, trademark and patent protection by videogame companies and their motivation - I recommend this excellent on-topic video essay by a real lawyer[1].
I am aware of trademark becoming generic words and losing protection. But that is a process of a trademark becoming so wide spread in usage that courts find that it is just a common word now. Courts look a common usage, not a tally of all the times the trademark holder didn't defend the trademark.
A trademark might still be generic-ified even if the holder attacks every use of it.
If Valve ignores this one, and decides to attack some other project selling something with a Portal trademark on it, the courts won't look at this case and say "but you didn't do anything that time".
The whole premise of "defend it or lose it" is a misunderstanding of how trademarks becoming generic.
Also, the aggressively protect your trademarks or lose them thing is a myth.