If the Apache group of tribes claimed that the word "Apache" was offensive, and managed to convince the USPTO that that was the case, maybe they could get the trademark rescinded, but that wouldn't mean they would get it for themselves, nor would it even mean the ASF would have to stop using the name, much less give up their website, only that they would no longer be able to sue other people for using it as well.
And bear in mind that trademark law does not aim to be a unique name registry. The trademark is issued in the context of the business. For example, the USPTO has trademarks registered for Apache helicopters and Apache skateboards, among others.
Those looking to "make a statement" can probably find the next lawsuit in that arena.