They actually moved away from Domination boosting damage, and instead baked the damage into the base damage scalar. By 'they' I mean the original studio. The reasoning behind it is dominators felt like they didn't 'dominate' outside of the button. You were gimped if you weren't in domination, because everything felt right inside of it. I think the same would happen, especially since it'd also apply against our max of 400% damage bonus, meaning we'd 'feel right' when we hit the button, but in a team, we'd not be getting as much of a damage buff as the next guy. We'd start basing our expectations of damage, even if it's 100% bonus, on how much damage we did during domination, and then in a fulcrum shift, feel like we missed out on that 100% damage that everyone else was getting.
Elec's control set might be able to take more damage, yeah. That, however, would just widen the gap between the efficiency of damage between controllers and dominators, where controllers auto-crit controlled enemies. If you want to make dominators feel more ... dominating, one probably needs to look at the passive, or the assault sets. Instead of boosting damage by a flat percent when domination is hit, doing an extra strike or a critical strike at 50% bonus damage on controlled targets (due to them having actual assault sets, not full blown control) might boost damage in a way appreciable to people rather than boosting base damage again, or fluffing up our damage and sinking that bonus we get from teaming away. Considering it's only impossible to control certain targets, we'd not be losing out that much?
Pretty sure giant monsters are really difficult to control, hence the problem against Babbage.
Also, forgive me if this is jumbly. Wrote this early in the morning for me.