Keep in mind there are stacking Sci Capt abilities which give large AoE resists and high aux HE also gives a large resists. Atm, there are far too many large heals in the game from boff powers, to sets, to doffs to be able to justify large resists. If they did away w/the heals, then resist spiking would be an alternative. But, that would change a lot about the design and require a lot of quality testing, planning, and communication of the when and why the changes are being made.
you justify large heals with large resists because ships have zero natural resistance (generally speaking). Other games have stuff like armor that naturally reduces incoming damage. In this game, you either react immediately or die.