It seems to be only a very recent introduction to the ceremonies, as I’m not sure whether or not that footage was included in the FOM world feed before 2009 at least.
Thus, it’s a good opportunity for the sponsor to get their branding some prime exposure. So they all started doing it.
I completely agree that it is totally unnecessary and chauvanist. What can be done about it? Not much, because I think it’s an agreement between the organiser of the race and the sponsor. Maybe FOM could set guidelines on acceptable commercial conduct of sponsors at F1 events, but that wouldn’t be likely.
One final thing, who else thinks that the clapping sounds like the applause at a dictator’s speech? They are told when to clap, and to not be the first person to stop.