I have noticed that most of the questions tagged as [streams] are about I/O in general rather than the STREAMS framework that the tag's wiki describes. Perhaps the tag is a little ambiguous?
STREAMS is rather obscure. Additionally, STREAMS is normally written all-uppercase but tag names are in lowercase. So it's understandable that people see streams and don't realize that it refers to some concept they don't know about. (Tag wiki? Who reads tag wikis?)
I don't think there's an ideal solution but renaming the tag should help. How about sysv-streams?