If you disagree with the basis of the hyperbole (i.e., that Gimp's UI is bad), the rest of the conversation derails, as seen with a few comments posted here. If you agree, then it fits and nothing goes wrong.
If you recommended listening to new band A instead of my preferred band B, I might listen to new band A. If you recommend new band A after saying my preferred band B sounds worse than a dying giraffe, I will probably be okay presuming I wouldn't enjoy new band A.
(I would, however, say that band C sounds like two dying giraffes, band D like a sick weasel, and band E like a happy songbird with bronchitis.)
Ah, OK. I do see what you're saying. At the same time, it's not really possible to come with an example that everyone's going to agree with. The author's point should still stand - regardless of how you feel about GIMP specifically, surely you've felt the same about some other app before.
If I said that some band "sounds worse than a dying giraffe", are you going to ask me how much worse it sounds, or what the giraffe is dying of?