UPDATE: This seems very related to: http://meta.workplace.stackexchange.com/questions/261/how-do-we-define-constructive-on-this-site
If it's not clear if the moderator should be involved, why is the moderator involved? You're right that moderators can't be expected to read every incoming answer - isn't that why we have community tools such as voting, multiple answers, and flags? Flagging is also supposed to be anonymous, to avoid retribution or flame wars between the OP/answerer and the flagger. Adding any kind of policy that requires a comment to make it clear to the moderator removes anonymity. I know that many people will comment anyway, even though they lose their anonymity, but that's their choice and it shouldn't be a requirement.
I'm failing to see where the problem is, however, I realize that might be due to my lack of visibility into the problem. I know that when I drop into chat occasionally there are lots of discussions about quality. The thing is, without full visibility into everything, including the moderator tools, it's hard to see the evidence for your point because I'm not getting the same view of the site that you are, or things like how many actions you're required to take as a moderator, what percentage of questions/answers are problematic, etc. I'm not asking for moderator access, I'm just asking for more information so I can more accurately account for what's being discusses and claimed about the quality issues. I want to bring this stuff into the light so we can all see it more clearly.
Along those lines, can you cite a few examples of where you're hearing complaints about the answers and not the questions (questions on meta, comments on specific posts, chat logs, etc.), so that we can all see them, and collectively discuss them?
Workplace.SE is a small community, but it's a community. Guidance is needed, yes, but if you're feeling you're needing to do too much already as a moderator (not saying you are, I'm just guessing at an interpretation of why you posted this), maybe there's an imbalance somewhere. Can we help you find it and work on it as a community?