In my experience lawyers are very conservative about this. I can believe that's the advice they're getting, but it's obviously not the full story. According to

In my experience lawyers are very conservative about this. I can believe that's the advice they're getting, but it's obviously not the full story. According to the eff[0] (article starts with some discussion irrelevant to this case). "The circumstances under which a company could actually lose a trademark—such as abandonment and genericide—are quite limited. Genericide occurs when a trademark becomes the standard term for a type of good (‘zipper’ and ‘escalator’ being two famous examples). This is very rare and would not be a problem for Canonical unless people start saying “Ubuntu” simply to mean “operating system.” Courts also set a very high bar to show abandonment (usually years of total non-use). Importantly, failure to enforce a mark against every potential infringer does not show abandonment. [0] https://www.eff.org/deeplinks/2013/11/trademark-law-does-not-require-companies-tirelessly-censor-internet https://www.eff.org/deeplinks/2013/11/trademark-law-does-not...