Hi Impulse, there are a few soprano players in the Room, myself included. Alto is my main instrument, but I dabble in soprano and tenor.
You're right, there aren't so many players who are known exclusively as soprano players, and in band or jam situations I've only seen about four or five, and of those all but one were doubling on other instruments (clarinet or tenor). The 'but one' was Lol Coxhill, and that was a few years back.
Some people consider the soprano an oddity or curio; I suppose in a way it is, I don't know that a soprano leading a jazz quartet could carry a whole gig, but I like the soprano sound and they are great fun to play once you get them to play in tune.
Cheers, Bob