I saw this scathing review of KY式日本語 on Amazon JP. This is the full sentence I'm asking about:
Ignoring the もまた part, what I get from this is
While a lot of books where I don't see the point of publishing has come out, a "book" of such pointlessness is rare.
When used together, もまた seems to be used a lot of times in the sense of "too" or "again", but it seems a bit odd if I interpreted it that way here.
I'm wondering if perhaps this definition from 大辞泉 is a better fit in this context.
④ （上にくる副詞を強めて）驚きいぶかしむ気持ちを表す。それにつけても。 「よく－そんなことが言えたものだ」 「どうして－そんなことをしたのだ」
(Side question: does 上にくる副詞 mean the adverbs that follows また?)
Though that would still leave me in the dark about も's function here.