Presta valves suck! (and not in the good way)
There, I said it. I know serious cyclists have preferred them since time immemorial, but I've been riding bikes with Presta valves for most of my natural life, they are simple, and effective, and I've never had one fail. I had some Presta on Tubies back in the day, and they were ok, but recently I've seen 3 fail on inner tubes. They are fiddly to deal with, the inner stem broke on one, and two others the stem came off altogether. OK, maybe I shouldn't a bought those $3 tubes, but I always buy $3 tubes, and never had a problem with the tubes or the valves before. I might be wrong, but they seem to leak more than Schraeder valves as well.
Schraeders are easier to use, and I've never known one to fail. Add to that the fact that you can always find a pump or an air compressor to fit a Shcraeader without an adapter, and I have to wonder why people bother with Presta? Is it just because they fit in a slightly smaller hole? It makes sense for tubulars, but on modern clincher rims, the difference in size is likely not an issue. I think we keep using them out of tradition, and for no other reason.
It's the Emperors new clothes people, and everyone's afraid to admit that we think Presta valves suck. We wouldn't put those big ugly Schraeder valves on a high-end bike, because then people might think it was a low end bike! I blame the French!