>>269657304x weak is actually pretty common in OU.
Scizor, Heatran, Bisharp, Breloom, Charizard Y, Talonflame, M-Diancie, Dragonite, Ferrothorn, Gliscor, Magnezone, Pinsir, Quagsire, Weavile, Tyranitar...
Reason being for those doubting, is most of the time 2x lands an OHKO anyway. 4x is just overkill. However, a consequence of being 4x weak to something, is you're dual typed, which gives you naturally better coverage, more than likely a load of resistances, and focuses the weaknesses into one. So you lose very little by being quad weak.
The only time quad weak really mattered was on something like weakness to Stealth Rock, which is passive, and wouldn't have been an OHKO no matter what. Of course, this gen, Gamefreak made a good move with Defog, so thats even less of a problem.