In fact you could make the opposite argument easily (that Pneuma is net negative):

* Pneuma deals no more damage than Dosis.
* It costs the same amount of time.
* Using it as a damage dealer "wastes" the healing that is free on top.

Hence from a damage perspective it's negative. Just continueing to cast Dosis provides the exact same damage and keeps the strong healing of Pneuma for when it is needed for healing reasons.

That's of course a somewhat silly argument, but it's just to illustrate that this is very much subjective. But also besides the point, we all know what is meant when someone compares Pneuma to Dosis for damage.