Why do want to keep government business off political committee's computers? Because once you do your government business at the RNC, the Congress can subpoena those computers and look at them. That is why. Can you imagine all the dirty laundry that will come out of the RNC?
And another thing, the Administration says they should not have to make their discussions, held in the White House, public as it would deprive them of good information. That is, they would not get good council from advisers if those advisers thought their discussions were not private. Sorry, I don't buy this line of bullshit. If you are doing the people's business then you should not say anything you would be embarrassed to have released to the public. There are national security issues, sure. But not everything else.