I think the boss fights are the most important part of the game and sometimes I don't feel like looking for the gate with a boss or just feel like fighting all the bosses at once. I thought that every theme should have a boss and either each tier or stratum has a boss at the end but what if it became too hard. A solution is that right before you enter a stratum with a boss there will be 2 elevators, one for the boss stratum and the other for a regular stratum. That way players can fight epic battles one after another if they choose.
True, if they're gonna put in those annoying energy gates might as well have something worthwhile behind them so you don't feel like a jackass for getting killed 2-3 times just for some red item boxes.