I think it is the best thing to do. If nobody cares if Heatran's Atk IV cannot be 31 but only 30, I'll take the 30 and stick to the game. In the same vein, if nobody is going to use OHKOs anyway, why would you ban them? There is no argument to make in favor of their banning, but there are plenty in favor of allowing (sticking true to the game, giving people more options).If it's not going to make a difference, being true to the game might not be the best thing to do.
Anyway, as I posted somewhere before, if it's consistency what you seek, then you won't be relying on OHKOs. Of course, the risk/reward thing is a tough nut to crack...which is why I like my Seaking idea (if you have to use Seaking or another suck Pokemon, the risk is increased, reward remains the same), but I cannot see anyone following that through, which is a shame.
Like Hipmonlee said before, shifting the game from one of skill to one of luck helps worse players over skilled ones more often, and in a similar vein, doing the reverse means skilled ones beat worse players more often. This means that in theory better players would stray away from OHKOs more often than worse ones.
Staying true to the game vs less emphasis on skill here pretty much.