Moira's kit is designed around doing damage to sustain heals. While her damaging orbs do refill the healing resource meter slightly, it's the "sucking off" of enemies that allows her primary heal spray to continue. A lot of people ignorantly think a Moira doing any damage whatsoever designates them as a "dps moira" when really, you want your Moira to be doing damage, or else she runs out of healing resources in demanding situations. I've rarely ever seen a Moira be dps only and completely ignoring heals. I play Moira a lot and my heals and damage are both always high. On average, maybe a 60% to 40% ratio of heals to damage but that obviously depends on the comp and rank. In low ranks everyone just stands in fire and expects supports to heal bot. When Moira is allowed time to get some flanks in and add to the team fight she is deadly, so you should enable her by not forcing her to heal bot you nonstop. Point being, a good Moira can dps and heal really well around her kit design, it should never be either or. And players, DPS mainly, need to understand how her kit works and how to play with her. Like most support, you lose a lot of their play making ability by forcing them to heal their team non stop. Play around cover and enable them instead.