"AB" has two different usages:
1. Quite contrary to A, (the fact is) B; Far from A, (it's) B
(B is the opposite of A)
> * 3
> *
> *
2. Not (just) A but even B; Even A is an understatement, (the fact is) B
(B is an extreme version of A)
> * 1
> *
> *
> *
Either way, B has to be something surprising.
As you can see in this question, the "traditional" usage is 1. Some learning resources mention only the first usage. However, the second usage is not uncommon, and at least this page and this page explain both usages.
In your example, the second usage is intended. Being is already bad, but the fact () is even worse.
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> Calling it a minority opinion is not enough; it's not even recognized as a theory.