This is the crux of the matter. A driver drives for a team and any communication with a driver whilst competing for, on behalf of, and as part of a team should be wholly restricted to that team. Officially, the 'competitor' is actually the team in any case, so any communication should be restricted to whomever any given team nominates in order to receive or conduct any such communication. Normally this will of course be a Team Principal - the 'captain of the whole ship'. Quite right too. The driver is just an employee, albeit a rather special one.
My feelings entirely. I wouldn't mind DRS but for the artifice of being given a virtually free overtake at a prescribed point on the track. It looks too much like manipulation of the racing; either let them use it when they want or remove it altogether. Yes, it may cause more accidents but these drivers are the best in the world and should know when and where to use it for themselves. Who DRS wins!