Earlier quoted context omitted.
Always been curious - what are some examples of trademarks being lost due to not being defended?
There's lots and lots of them. Have you ridden an escalator® lately? https://en.wikipedia.org/wiki/List_of_generic_and_genericize...
Again, IANAL but we do need to stop spreading FUD about what trademarks entail. Trademarks are meant to protect a brand from being diluted or confused, not to police the world of all parody or reference to some thing. In fact, if the store in the game wasn't even called an IKEA, I am really curious what "trademark" they felt it violated, but unfortunately not curious enough to find out.
P.S.: a better example of a trademark that fell to non-use would be "Twitter". However I personally dunno if there is a trademark that fell specifically because they didn't bully enough people who tried to use their trademark in ways that wouldn't be confused with their brand. That seems to be a made-up invention by corporate lawyers that people just accept at face value. If it really worked this way, the mark "JavaScript" should've fallen a long time ago.