It's actually kind of obnoxious to call on people like that. Even if it may seem like a "leadership thing" -- which may explain why it seems such a favored technique among wannabe alpha manger types.
I'm with the parent commenter: if people are in the flow (and give a shit), they'll definitely have something say (and your difficulty will be in getting them to keep it short). If they're not, and you're getting crickets -- it points to a deeper problem. That cannot be solved by, in effect, throwing chalk at people to get them to speak up.