Pretty much what Mike said... It seems like guys who make their strikers with thinner shafts tend to flare the tips on their strikers to allow for more contact between the striker tip and the playing surface, thus making playability easier. If I make my strikers with a 5/16" diameter shaft I typically keep a straight striker tip, if I make a thinner shaft I will typically flare the tip on the striker, of course there are always exceptions. I wouldn't say for either is done for looks, but some guys just prefer one over the other. I was always a flared guy myself, but have recently been finding myself running my straight tips more often...