In my bracket (silver) Moira’s often a faux Symmetra. She’s a DPS and you don’t count her as a healer if you want you’re team to get any heals.
They do it because she soft locks when targeting and her orbs do fast damage. They do it because they think damage is ALWAYS better than heals.
But then again in my bracket everyone’s fine on going five DPS and one support too.
Sigh