I like the idea.
Perhaps a better way to do it for those wanting "realism" would be that DCS would track their g-excursions, and their planes would degrade over time. Eventually their planes would break, and they would have to buy a new one. If their over-g behavior doesn't change, they could be kicked out of their simulated military and not be allowed to fly in the future.
All that being said, a server level g limit would be easier and allow those who want to fly according to NATOPS do so, and those who want to play as Dale "Snort" Snodgrass could play on the servers not enforcing these limits.
Do it Eagle Dynamics!