Yeah, there's something about that one (and the K-31 that followed) that just looks "off" to many American shooters and firearms collectors. Probably because for so many years, they were a true oddity compared with the world wars' Enfields, Mausers, Mosins and Springfields. Of course, the Swiss rifles, when seen up close, as a delight to anyone who appreciates the machinist's art.
Some of that Swiss weirdness trickled down into the rifle that followed the K-31, the Sturmgewehr 57:
That one is a candidate for the ugly gun list, too - though recent years have seen replacement grips, buttstocks, rail systems and such which make it look a lot more "generic black rifle". I'm just not sure if that's good or bad.