Basic economics explains how the concierge rates help keep the lowest categories at very low fares. Just do the math of having 2 people in a Cat. T versus 4 in the lowest rate inside stateroom. Include feeding and entertaining. Last I looked, everybody eats in the same restaurants and has access to the same shows.
As for the gates, they are not in use to restrict passengers going through the concierge decks. You do have to have concierge access to use the concierge lounge and the concierge sundeck.
I won't pay what
DCL asks for a royal on the Dream class ships. I cannot justify the expense.
To give you an idea of background, our first cruise was on the Big Red Boat. We sailed with Mickey. This is where the basis for DCL was born. After Mickey stopped sailing, when DCL was announced, Bugs Bunny & pals took to the seas on the Big Red Boat. We were not as comfortable financially then as we are now, so a stateroom with a porthole was the best we could afford. I choose to book concierge, not for the service or the idea of being above the little people( this idea comes up when anyone sailing concierge mentions things they don't like or are confused when shore side concierge asks for requests). No, I book concierge for the added space. I book a Cat T or above because I want the multiple bathrooms, a dining area and the ability to enjoy MDR food in the privacy of my stateroom, the large verandah that my stateroom offers. When we sail out of Port Canaveral, I am outside on my verandah, sipping champagne and enjoying my All Hands On Deck cheese plate from room service. That is when my cruise begins and I don't even notice that I am surrounded by thousands of others enjoying the start of a DCL vacation.