"He is not much good" — correct with "much". "She didn't look much disappointed" — is this correct with "much" too?

Question

from an answer on ell.stackexchange.com:

If "much" qualifies a simple adverb or a simple adjective, you can use it in a negative sentence:
(1) He is not much good. — OK

The word "simple" makes the rule very bad and unclear because it's not understood what "simple" means.
Is the past participle adjective "disappointed" considered simple or not?

for example:
(2) She didn't look much disappointed.
Is (2) correct?

P.S.: I know I can say (1) and (2) with "very":
(1a) He is not very good. — correct
(2a) She didn't look very disappointed. — correct

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Also I wonder whether adding "very" to "much" would change the correctness of the sentences or not:
(1b) He is not very much good.
(2b) She didn't look very much disappointed.
Are (1b) and (2b) correct?

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Answer 1

I need to hammer this nail. Why did you hand me a screwdriver? A screwdriver's not much good.

That is, a screwdriver is ill-suited for hammering.

When I told him there was no Santa Claus, he didn't look much disappointed. Perhaps one of his fellow students at the university had already told him?

Common in the 19th century and earlier, "much disappointed" is grammatical but has now been ousted by very, at least in American English. Until around the middle of the 20th century, authors on "correct" use of the language were insisting that much be used with participial adjectives.

The house was much dilapidated. ^obsolescent

much can be synonymous with "a lot" or "often" or "a good deal":

Do you run much?

Do you ski much?

You're gasping for breath after a few jumping jacks. Exercise much?

But the answer cannot use much in the affirmative:

Yes, I run much. ^{ungrammatical}

No, I don't exercise much. ^grammatical

Answer 2

"not much good" is a special case. Generally "not much" is followed by a comparative adjective, e.g. "not much stupider/better/taller", a mass noun e.g. "not much sugar", or a countable noun with "of", e.g. "not much of a man".

There are other similar constructions like "not much use", "not much help", "not much point", where "use", "help", and "point" are nouns. So it might be assumed that "good" is a noun here, which it can be (Merriam-Webster), not an adjective.

So the rule would be

1. "Not much good" is fine.

2. "Not much" + comparative is fine.

3. "Not much" + mass noun is fine.

4. "Not much"+simple (non-comparative) adjective is not idiomatic.