This question already has an answer here:
I have been paying more attention to the suggested edits pending approval area in my shiny new 10K tools, and I have noticed (just a few) very poor suggested edits.
Reputation is a rough measure of how much the community trusts you. Awarding people +2 reputation makes sense because of this. You're reputable because you suggested an edit that (at least two of) the community agrees with.
However, I think people should also be penalized for a rejected edit. Perhaps -1 reputation, or something more creative (like 5 rejected edits in a week results in -1 reputation).
In my opinion, the other side of reputation is not represented in the suggested edit process.
To me, this is similar to deciding an answer is useful (upvoting) and deciding an answer is not useful (downvoting).