Well, because the beetleweight category over here as far as I'm aware is still in its infancy, I don't think people have quite perfected things yet so I guess there'd be more of a chance of being competitive there if you happen to get a setup that works well, but on the other hand people know what works with featherweights and you'll be able to borrow ideas from established machines and make a decent go of it right from the start and know you'll be relatively competitive from the off

Really, it doesn't matter too much I'd say. Go with whichever you'd prefer!