Apple vs. Apfelroute - A bike path through a apple producing region https://www.welt.de/wirtschaft/article192836621/Apple-will-A...
Apple vs. Apfelkind - A small coffeeshop https://www.dw.com/en/german-caf%C3%A9-owner-takes-on-apple-...
For instance Wendy's sued a local snackbar here in the Netherlands called "Wendy's". Same here, they somehow expected to win because they're big? [0]
[0]: https://www.volkskrant.nl/economie/zelfs-wendy-s-krijgt-wend... (Archive link: http://archive.is/oiFWv)
Actually I can see the relevance here, especially for that first case.
But as others probably mentioned already, if you don't actively defend your trademark it becomes void and you actually lose it. They don't do it for profit, as this actually costs them money. They rather don't really have any other option than doing that. Well, run the risk of losing the trademark of course. However the case with the pear confuses me, too ...
There's also a difference between defending your trademark and going after things were the overlap is vague at best (e.g. the pear thing).
Most of that is a myth, because people keep mixing it up with protected designs, names and the like. Trademarks are another league, though. Otherwise we'd have plenty of real estate businesses called Coca Cola and Apple with equally designed logos for example, and cases like Apple vs some Café would just disappear or not happen at all. Again, they don't do this for fun and giggles. It costs money and is necessary.