As noted above, I think you could say that it's difficult to make one that cycles the slide (reliably).
Glock wanted the same manual of arms as their centerfires, therefore it must cycle the slide.
The good ones, Hall-of-Famers in you will, cycle the bolt.
I don't fully agree, though. It's true that many of the famously reliable .22lr semiautos cycle a bolt rather than a slide, but other makers have achieved cycling the slide with success. This includes lesser-regarded manufacturers than Glock. For example the Bersa Thunder .22 has an overwhelmingly positive reputation... And its intent is the same, it completely replicates the manual of arms for its larger-caliber equivalent. I suppose it's hard for me to believe Bersa is capable of something that Glock isn't.
Now granted, maybe it's less of an engineering challenge for Bersa because the full caliber pistol is also blowback operated. But there are at least a few blowback .22 replicas of locked breech pistols that work well and hold up with use. There are .22 versions of 1911's, S&W M&P's, for example; and they are pretty good.