I think the only thing we can all agree on is that no solution will please everyone. Some people want the tiers by nights, dollars, cruises, etc. In the end of the day, the only thing that matters is what DISNEY thinks is the right way to do it. They could have taken the opportunity to change it up when introducing Pearl, but they didn't, so my guess is they have ZERO plans to do so anytime, at least in the next decade. THEY value the number of cruises you take, and that is what they "reward". Take it or leave it.
Now the value of that reward is something I think we all collectively agree is lacking. Other cruise lines give significantly better perks for loyalty. When I hit Diamond on Royal (which took me 12 cruises to hit and I feel is a comparable expression of my loyalty to Royal as my Platinum status is to Disney), the perks were significant. 4 free drinks per day, a free photo, discounts on Wifi, top-tier events on the ship, etc. I have spent far more money on Royal than Disney because I know when I go, I get value for that loyalty.
I love
DCL, and I will continue to cruise it, but business is business (both from Disney's perspective AND MINE!) As long as Disney thinks that reducing perks and nickel & diming is the way to increase profits, then I will choose to make them my #2 cruise line. I love both experiences, but Royal does a better job of enticing me back with the perks.
In the end of the day, I feel this is all because DCL just doesn't have enough ships. Yes they have too many Platinums for the size of the fleet. So the only options are to water down the Platinum benefits, or build more ships at a faster pace. I feel they are doing both. But it takes time to build ships. Taking away perks is easy, but petty. If you are cruising DCL because like me, you love it, then that's great! If you are cruising it because of the expected loyalty, you will be disappointed.
At the rate we cruise, I will likely hit Pearl on Disney around the exact same time as I hit Diamond+ on Royal within the next 3-5 years. I expect to still get far greater value out of the D+ status than the Pearl.