It doesn't give BitPay decision-making power, it gives them the power to make proposals.
God, if I wanted I could contribute to the core development, just as anyone, would that mean I control Bitcoin ? Not more than any of us !
Code's changes still have to be reviewed by the community and other developers, and don't worry, a lot of people cares about that (you can see the polemic on dust outputs).

So chill out, and thank BitPay for their contribution (it's not selfless, but keep in mind they need Bitcoin to be a success for their business to run).