If people feel the need to hear "café noise", maybe it's just a sign of loneliness?
And if you need white/pink/whatever-noise, maybe your office should integrate some noise policies or try to reduce noise by giving offices to small teams of people.
I get that people use those audio streams and soundfiles to "shut off distractions", but to me, this is only a fix to a bigger problem.
Edit: Maybe someone should start beerbarsound.com, so you feel like you're out drinking with your friends, but in reality you're sitting at home/the office, working, without any friends.