I don't think Feige and co. understand what makes Adam Warlock appealing. Most MCU heroes are mostly good at two things: quipping and mugging for the screen before quipping some more. It's almost like the villains are antagonists only because the heroes stole the screen time from them.
Jim Starlin's Warlock isn't that. He's a brooding character that deals with religious satire, trippy metaphysical stuff and the line between sanity and insanity.