well you might not have the time, but i seem to manage it just fine. You aren't always being attacked by good players. And Even if you are, its still real easy to switch targets throw a bubble and switch back. There is no reason why a DPS sage shouldn't have over 200K healing when your team doesn't have a real healer. I have put up over 450K healing as a dps sage. And Many ganes with 300K+ damage 280K+ healing. But I like winning so I do whatever I can to help win. If we have good healers then yes I will DPS non stop.There is always time for a dps to throw heals. Hell my dps commandos heals are way worst then my sages and I have put up 270k healing in a full dps spec. Bioware gave us these skills to use. Stop letting your teammates die because you are dps.
It sounds to me like you don't get to face many good players. Good players aren't going to let themselves get caught out of line-of-healer-sight. The more time you spend bubbling your team-mates and incurring the penalty of having to reapply your kiting rotation to give you some distance, the more time the enemies are being healed. It also begs the question why your team was without a healer.
If you had one, you guys clearly failed at protecting/peeling for them if you feel the need to bubble team-mates. If you didn't have one, then you clearly failed as a sorcerer to respec heals to help your team.
Don't get me wrong. I'm not saying you should never bubble your team-mates when healers aren't around. I'm saying that if you have the time to bubble your team-mates as a DPS sorcerer you aren't facing very good players.