Macman, 100 % Just the mess and that I dont keep the shop heated. I peck, peck, but occasionally I guess I got impatient.
Lucky, I would not have to take the tooth back simply to convert to square filed. It really takes only a few file strokes as all of the round ground surfaces do not have to be removed at once. Just the very point of the tooth and a bit of material on the inside corner of the tooth that is the most in the way of initial chip formation. We have been all told to make good firm file contact and not let it skitter or it will dull quicker. Especially with the left hand I am weak in this respect so the chisel files seem not to last too long sometimes. I use the round grinder to make a uniform gullet shape and set the rake angle when I am working up a chain for bragging. That rake angle sets the file rotation, and the top plate angle, so only have to eyeball the rearward tilt of the file as it skims the side of my clamp. The keeping file corner on or just below tooth corner also has to be watched. There just are a lot of dimensions that have to be controlled simultaneously as opposed to only 2 on roundfiling, but you begin to do it automatically after a while and even git to put your tongue back in and chew gum!