That's a myth. It suits trademark lawyers and aggressive owners to pretend this is obligatory but it isn't.
Genericization occurs when more or less everybody uses your word mark instead of a generic product class. But you can't actually sue everybody. And if you chase say, popular media, it just becomes a joke - Stephen Colbert can't use the word literally everybody you know uses because his bosses will get sued, ha ha, but it doesn't stop you and it won't stop genericization from happening. Notice you won't find any courts checking that you spent enough on legal fees as otherwise you lose for inadequate enforcement. They only care that ordinary people, who you wouldn't sue anyway, used this word in a generic way.
Beyond that, it's not at all obvious that this is a problem you'd want to prevent. Why are Kleenex and Xerox so well known? It's surely not because they're unsuccessful!
If someone makes a patch and publishes it, the rightsholders do have a case against whoever published it, but that requires enforcement in the form of a C&D or a lawsuit. The rightsholder might very well decide to not do anything about it, which happens fairly commonly.
This is not a substantial barrier for making a patch like that.