I simply believed OU was more complicated since there were 40 or so commonly seen Pokemon that had to be countered while I kept seeing (at the time I joined Shoddy) only Ambipom, Swellow, Sceptile I think, Mismagius and Azumarill. I'd assumed after watching a few matches that UU was less powerful = simple. It is not. Less raw ability means it must still be used tactically and carefully. :/