Trademarks are granted in specific categories. Wendy's restaurant can have a trademark on "Wendy's" (the rendering of the name in a specific font, the pigtailed girl logo - these are different trademarks than the word mark using "Wendy's"), and Wendy's craft supplies can also have a trademark. Pretty straightforward defense when the hamburger company gets annoying; hard to argue that pins-and-needles can be confused with hamburgers.

But I see your point. I do wonder if any of these defendants have added 'the term is descriptive, and therefore indefensible' to their defense.