When flagging an answer as "low quality" you see some explanatory text that reads:
This answer has serious formatting or content issues and might not be salvageable.
An effort should be made to improve answers before they're flagged for removal. I don't mean to discourage any "low quality" flagging at all, so if an answer is old and the user hasn't been back for a while, go ahead and flag it. But if an answer is only a few hours old and has no downvotes or comments (meaning no one made an effort to communicate that improvement was needed) then I'm hesitant to just delete it.
Moderators just don't have time to look at every low-quality answer on the site. We need everyone in the community to use the tools at their disposal (downvotes, comments, edits) to deal with these. Please use flagging for deletion as a last resort.
Naturally this is open for discussion, so feel free to voice your opinion if you disagree with me.