It's possible that a mathematician with philosophical commitments is more likely to be a Platonist than a formalist, but I suspect that most mathematicians are neither ("Philosophy is for the philosophers"). The so-called "naive" view that most mathematicians may be described as having ("I'm discovering something real when I prove a theorem", "Mathematics is objective", and so on) certainly sounds similar to the language used by Platonists, but I have yet to run into a mathematician who is comfortable with the logical conclusions of a strict Platonism. In particular, there are epistemological problems with Platonism (how can we know anything about non-physical entities?) that cause problems in the justification of mathematics and would be nice to be able to ignore.