I am a sorcerer myself. I think your understanding of the mechanic isn't perfect, but whatever. The mechanic began in WoW in PVE for healing classes that don't take much damage to keep up force/mana/whatever. It obviously isn't force efficient to damage/heal yourself, and if you're using the mechanic for that reason in PVP then you're using it wrong.
To your example... both cases helped the team, right? If DPS were "mash[ing] damage abilities" (lol) then they're doing their job and helping the team, regardless of individual ability. If you put up 150k or 400k, you were trying your best and helping the team. Why would you support an error in stat recording that encourages laziness and for people to not help the objective?
The numbers do not bother me too much. I am bothered when I see people giving up on a losing game or not trying to help the team. I don't understand the ridiculous reaction of some people... I'm not demanding a change or threatening a sub or anything. I'm suggesting a minor change to support team-based play and fair stat distribution. On an 8 person team, if one person isn't contributing it makes a huge difference.
This change would aim to fix an issue that a small minority of sorcerers/sages abuse. Again, I am a sorcerer myself!
@Keiret and the others with a brain... thank you for your support. You understand my point exactly.