On bug 1271478 starting at comment 39 a single user action created 5 bugzilla comments. It would keep the bug much cleaner if this only created a single new comment.
I understand your pain, but there's not much we can do about that directly, given that (a) people like BMO review flags for MozReview requests, which necessitates one attachment per commit and (b) Bugzilla is heavily architected around individual attachment actions (combining them would be a massive change, I'm told). Instead, we're looking to mitigate the effects of all these comments by tagging them (bug 1226080) to make them easily collapsible (and possibly autocollapsed, but not entirely sure there). Furthermore we want to "supercollapse" chains of collapsed bugs (bug 1226488) to further reduce noise. I'm going to dupe this over to 1226080, which should be fixed before too long.