On the "featured deep discounts," usually they have classic or semi-classic games there that typically are somewhat old, but highly reviewed by players on Steam. Like in the last few sales they were typically like 85%+ positive reviewed.

Indeed, the Steam store page says of "featured deep discounts" games... "ESPECIALLY GREAT DEALS ON SOME OF THE ALL-TIME GREATS"

I mean the page is supposed to have GREAT games not games with average or bad review scores I would guess... lol.

Destiny 2: Lightfall is on there for me and it has "mostly negative" reviews. Mafia 3 is on there and has "mixed" reviews.

I wouldn't exactly say something is an "all-time great" game if it has "mostly negative" or "mixed" reviews, typically...

Maybe I'm unusual but I'd even rather see highly rated indies, older games, or AA games there than a sub-par AAA game.