In the comics Dr. Stephen Strange is brilliant, enigmatic, and snarky. Any humor is a result of these traits. He’s not jokey. Nor affable. (i.e. Stephen Strange isn’t Tony Stark)
The movie version can’t decide if Strange is funny or not. It seems Cumberbatch played it mostly as “not.” But there were scripted moments that probably would have worked well – If RDJ was performing them.
They should have picked a direction and stuck with it. Personally, I would have gone with a version that was more in line with the comics, but I understand suits are nervous about “unlikable” leads. Which, I think, Strange is pretty unlikable most of the time. Borderline insufferable. But that doesn’t mean he’s not interesting, compelling, and easy to root for.
Sounds rather Sherlockian, eh? We know Cumberbatch excels at performing that kind of character. Maybe that was part of the problem? They were afraid of seeming like Magic Sherlock? (Sounds awesome to me.)
Missing Character Arc
At the beginning of the movie Strange is fundamentally a selfish character. At the end, he’s still fundamentally a selfish character. He has learned a lot technically; instead of being a master surgeon he’s a master sorcerer. But he’s not grown as a person. At all. Yes, he “misses” his ex-girlfriend. But that’s not an arc, that’s just more selfishness.
“But he sacrificed himself to defeat Dormammu!” I hear you say.
“Yeah well, not really.” I reply. He was essentially immortal in that time loop. It was a clever gambit that couldn’t have resulted in his death. Insanity perhaps, but not death. As a tactic, it was well calculated. It does seem likely that a being with no previous concept of time would go mad before he would.