First game protagonist motivations

[Udenszirnis]

Seriously, what is the deal with them? Scar went from a mercenary to a C-consciousness pro-zone simp, Strelok turned his motivation from "the zone must disappear" to "let me turn it into a nature reserve for fun" and Degtyarev is spending his days as the policeman of Pripyat, supposedly the only one with a group strong enough to stand up to the Monolith? Monolith kicked everyones ass except Degtyarevs, and he just kinda hangs around the are for no reason other than to kill more Monolith?

[Coldhands]

Wasn't Scar always working for C-Consciousness? I can't remember now.
Strelok is tough because there were multiple endings to ShoC, and I guess they went with him destroying C-Consciousness as the canon one ... but the actual impact of that ending kinda seemed like it should be more profound than it ended up being.
Honestly, I don't think it's a great idea to have previous protagonists as NPCs in games in general.

But the weirdest part of all this is that Monolith goes from a handful of survivors on Wild Island to a zillion dudes with loads of high-end gear pouring into The Zone at the flip of a switch. Where were they all hiding this whole time?