By this same logic, the Niuweidao should be vastly better than the Liuyedao. However, most cRPG players would gladly take 1 speed over 1 cut damage, which explains why the Liuyedao is actually about TWICE as popular as the Niuweidao (according to the most recently-posted NA server stats).
Now, the Elite Scimitar happens to be the most popular 1h in NA (way more popular than the Scimitar), but I don't think that has anything to do with more glancing as you claim. At least on NA, the Elite Scimitar achieved legendary status in the hands of Balbaroth, and I think he inspired hoards of copycats (he hasn't played in like a year, but I still see people wearing his gear combo).
The extreme curvature of the regular Scimitar makes it look odd (both for the wielder and opponents), and I guess people just don't like the aesthetics. Stats-wise, the regular Scimitar is quite nice (it's the fastest 1h weapon with anywhere near that much reach), so it's all in your head.
The blade is illusive, that's all there is to it.