I think part of the answer is to stop the cross-overs with Celebrity, or turn Celebrity into a points system more in keeping with RCL.
They have already broke the D+ at the 350 and 500 mark. They just need to name them.
However, if they start booting the D+ from the concierge lounge, they will once again find themselves in trouble. They have added or are still adding Diamond Lounges to their ships - they can't keep changing the goals posts as everyone seems to want them to do..
It appears to me that those that gripe the most are already there and don't want to share with those coming up behind them.
D+ and pinnacles seem to flock to the TA's - I assume because by the time most are at that point, they have more time on their hands
Perhaps on those cruises they could do what Celebrity does and just hand out 3 vouchers per person per night.
Oh, they could stop handing unearned status to family members as well. Make everyone earn it on their own. Also, make really sure those walking in the door are actually eligible. It seems to me about 15% to 25% of those in the lounge should not be there.
Overall, I think there are ways of handling this without kicking those that earned it out.
(Not a poor loser here - D+ for what itès worth.)