Why not sign?
Something in my real life brought this debate back to mind.
Is there any justification for Steve just refusing, period, to sign the accords?
I would've been against it, and WAS against it, up until the scene in Berlin when Tony outright explains to Steve that there are provisions for amendment and exceptions built in.
In other words, the Accords were a typically overwritten piece of legislation specifically intended to put people's minds at ease about superpowered being among them.
But if things "go sideways" and Cap feels the need to get involved, is there any doubt whatsoever that Stark could hire the planet's best lawyers to find exceptions in that huge document? Or use the Avengers' immediate action to carve out amendments and exceptions?
I dunno, seems a bit TOO stubborn and blind to reality for Steve to not even consider it.