If you're going to lump them in with Stan, Jack and Walt then those three should be Grand Poobas or something beyond Master.
But in the era where everything is EPIC, I suppose you're right. Mediocrity should stand hunchback to shoulder with the best. It's only fair. Wouldn't want to hurt anyone's feelings. I'm surprised you dislike Aaron's work so much. Seems right up your alley.
Even if the word "master" has various meanings, the definition that best suits this topic is "one who is a skilled practitioner of an art".
Walt Simonson made his mark on Thor. Doug Moench made his mark on Batman. Tom DeFalco made his mark on Spider-man and as part of the creative team that developed GI Joe and Transformers. All three are contemporaries of each other. All three deserve proper respect.
And, snide remark aside, they should stand shoulder to shoulder with the other greats during the 80s and early 90s.