Right, this is what people always say about Arch. And yet, in practice, on a variety of hardware, I've had nary a problem in the four years I've been using it. Contrast this with big-release distros, where I've literally never had a successful upgrade between major versions. But maybe the key point is in your second sentence. I've never had a problem with Gnome breaking because I have no interest in running a DE, and even on those systems where I've got one installed, I boot to the console and start i3 or sway. If Gnome was broken, I'd never notice.

And this might be the key point: if a package like Gnome is broken, I personally blame the package rather than the OS. I don't see a GUI desktop as integral to the operating system, so when I say that Arch has been trouble-free, I mean that I'm always able to boot to a usable system console and get my work done. So that's my disclaimer, and probably the big reason people shouldn't use Arch: if you rely on a DE, and see the system as broken without one, you're probably going to experience way more breakage than I've reported.