Frowned upon by whom? I seem to recall Christian theologians jumping through logical hoops for millennia to preserve both free will and an all-knowing God, specifically so that it would be just when God tortures people for eternity for sinning.
Edit: But you can't have sin without free will, per Christian theology, if that's what you're getting at. Same way you can't have not-sin without free will.
A lot of people have half-cocked, pseudo-theological ideology they've formed from surface-level understanding of various texts and online forum psychology discussions.