Beer industry people who do this on Untappd are the absolute worst. Like, really, I'm not sure I can think of a beer-related thing I like less. As far as I'm concerned, if you work for a brewery, you shouldn't even be rating a beer on Untappd with stars.
EDIT: I will say, Sixpoint (and maybe others, I can't remember) have commented on bad ratings checkins I've had that have a comment about the beer perhaps being off, which I don't really have any issue with, as long as they're just trying to figure out if they have a QC issue.