Well, if it was like DoI and we could add a radio to the Rifleman class, I'd be fine with it as is.
Given that's not an option here, I don't think that taking Observer to get a capture bonus, while ignoring the core duties of the role, is good teamplay.
I'd be just as annoyed if someone took Gunner and went pistol only, or took Demolitions and refused to take out technicals.
The class system, for better or worse, is something that needs to be played within to have teams at full operational capacity, so taking classes that are necessary and doing your own thing is something I think would warrant stripping the role from you to give to someone who will do the job.
Maybe the fix here is to have a "tactical radio" or other gear that breachers/riflemen can carry to boost cap speed, so that we don't have to fight over the classes?