I agree that too much bold and italic type has been used for some suggested edits, and that the resulting question or answer is harder to read. The pointI think it is better that we should spend time improvingto improve the quality of the posts, and not just dress them up in too much markupby simply highlighting words.
Even though I usually reject edits with too much markup, I have decided now that if I come across an otherwise legitimate edit spotted with markup, I will simply edit it out the unnecessary markup myself and then confirm the edit. However, if the edit has too much markup and is too minor anyway, it should still be rejected.
In cases where there was too much markup in a suggested edit, we can leave a note saying why we have 're-edited' it to remove some of that decoration. Then we won't lose valuable contributions and if the user who proposed the edit looks at the edit history, he will understand.
This is not to say we are the final arbiters of style; it is a subjective thing, but rough style guides do already exist across the network. See, for example,