Personally, I've always been a fan of the infectious, insidious taint. It provides a horror element that I really enjoy, and I always felt that changing the taint into something that is only voluntary takes a certain.. edge away from it. But I have always felt that Tragedy (with a capital t) always has a place of prominence in any samurai story, and doing your best to beat back the dark tide and finding yourself slowly succumb to it yourself despite your best efforts is just pure gold for any samurai tale.
It's also easy enough to avoid... You just don't include this one single element of the game. I mean, if you are playing something like HOR or some other sort of pre-written adventures than it's a bit more difficult, but if you really don't like dealing with the Taint it should be something you bring up to the GM when you guys are talking about the Pitch before play begins.