For the general user on here, they aren't using RPC.
If you are in a corporate environment, then it is obviously more feasible that you are going to have machines talking to each other that need it.
Still, that only rules out the software firewall on that machine from blocking ports.
You can still put a firewall on the outside connction to block said ports from coming in.
And again, for those that have to get their word in, of course won't work if you are making remote procedure calls, then fine - you might have issues.
But I stand by my statement that the users on here aren't in need of those ports, and are better served by blocking them.