Here’s my overall argument for why I don’t think healing PSes are more powerful than damage PSes:
Damage is permanent, Healing is temporary
What I mean by this is that if you do enough damage to reduce an enemy to 0, they’re dead. They will no longer be taking space, nor damaging, nor doing jack shit, on account if they’re dead.
No such thing exists for healing — if you cap somebody’s health, it doesn’t mean anything in and of itself.
2 damage is useful insofar as it gets you closer to killing the enemy — you’re not worrying about a constant or unknown flow of enemy health so much as you are just calculating your chances of murder. Though it’s still kinda weak late game, 2 damage can get you to the goal point of 0.
Healing is useful for two things: getting other players off of the ground, and maybe letting them survive an additional attack (rather than reaching a goal of points healed, you’re just trying to keep them from dying to the next burst of damage, which is flexible). The former doesn’t suuuuper much matter for the purpose of healing PSes, seeing as with the halved healing downed people you get 1 health from a +2 MAG PS or 2 health from a +5 heal PS, and that’s not gonna save someone at low health from an attack either way.
It’s a bit different with the latter. Seeing as capping health doesn’t really mean anything, the use of a healing PS pretty much entirely boils down to whether or not it’ll help survive an attack. 2 health is, even with fairly tanky units, a small enough total that it’ll almost never make the difference, and thusly a +2 MAG PS for a unit who only heals is very near to useless. +5 healing is a fairly useful difference, though.
Plus I don’t get any bonus to healing from AS, I don’t get crit with healing, and I don’t get any bonus from hit for healing. With healing PSes being banned there is very very little I can do to actually meaningfully increase my healing, whereas attacking people get like four different ways to do so, and that is frustrating. If I were playing a pure healer (and with how much I’ll have to do as the sole healer I’ll be very close to one anyway), I wouldn’t be able to invest my personal skills into anything but staying alive. Or MOV, but MOV PSes are an entire other kettle of fish.