I'm a left hand shooter, and for most guns, I prefer left hand actions, just for the chance that I would hunt with it and might need a quick follow-up shot. The left hand action is quite natural even though I am naturally right handed. I even shoot handguns, righthanded.

But for bench shooting, I think you make an interesting observation. I almost always single feed each round, inspect the fired brass, load the next round, etc. Using a right hand action, it's much easier for me to catch the fired brass and load the next round, without moving my 'shooting hand.' And even more, the recoil of my .270 sometimes causes the bolt handle to hit my hand--that can't happen with a right action.

Despite these advantages, nearly all my bolt guns are left handed! In fact, I just purchased a 30-06 from a local owner, only because it was a left action. Yes, old habits are hard to break.