Being both a vintage fan and a rider in the process of building my first fixie conversion, I think it's pretty hypocritical for any vintage-purist to criticize a ss/fixed rider for 'ruining' a frame purely for aesthetics - just because vintage aesthetics don't (usually) involve modifying the frame, it doesn’t mean that the NOS crowd isn't every bit as fixated on looks. Different bikes for different ideals.

I was into computer case modification a few years ago. For one computer, I spend hours soldering extra lengths of wire onto every part so that I could route all the power cables along the outer edges of the case - to make sure I had a nice clean look on the inside (to view through the lexan window). Cables running all over the place never looks that good, and neither does a lot of unnecessary clutter; in a computer or on a bike frame it just looks a little sloppy.

Vintage bikes and conversions are a lot cheaper than track bikes (unless one is lucky), so I can completely understand why someone would chop off the unnecessary bits from an older frame - they want to dedicate that bike to being fixed gear and there's nothing wrong with that - it wouldn't be getting any use otherwise.

I'll completely agree that if people are chopping braze-on's off of Paramounts, PX-10's, or other highly collectable bikes, but I really haven't seen much of that. I'm building up an 86-87 Peugeot fixie, lower end frame, and will probably chop off the unnecessary things. The frame's got a dent in the top tube, wasn't that great to start with, and had components that were nearly impossible to replace. Assuming I can match the pain colors, I'm not going to feel guilty going at the frame with a dremel. Even if I ruin it's chances of being built up to stock again, it'll still be getting much more attention and ride time than it ever would have otherwise.