Welling is the same as 99% of all actors, he takes the advice of his agent. Actors act, they don't generally know shit managing careers or quality of scripts, so they hire professionals.
Oh, puh-LEEZE. What a steamy load ...
You know, I'll be the first to say I over simplified that for the sake of brief post.
But maybe you could open up a little and tell me why you think that instead of just mouthing off?
Meanwhile, a very very very tiny percentage of actors have vetos over scripts or are allowed to rewrite their own material. When Welling started out and was signing his contract he wasn't in that league. He's not in that league now. He's not a writer. He may be a good reader, in the sense that he looks into what he's reading and considerers the source material, but we don't know that. A good actor follows direction.
Actors don't manage their own careers when they start out, and very rarely when they are experienced. Welling didn't write his first contract, he didn't write in his vetos, and he had no huge negotiating power. His agent did the work he was paid to do.
The studio and producers of Smallville had all the power to refuse Welling and his agent when they wanted that stipulation, the fact is they were going that direction anyway. If they weren't then they wouldn't have agreed.
If you think that's a pile of steaming shit, you're welcome to explain why.