Why would they not be able to use obli? Obli works on everyone, it doesn't only work vs templars.
That is the problem with templars though...they are so OP and so damaging to the game mechanics that people start to think like you do. What you are saying is obli is an anti-templar skill because their damage is so high, whenever a templar is fighting against your group, they are the one that determines when the obli gets popped.
I'm not misunderstanding you at all...its the same dumb **** ShadowAce tried to argue with vacuum being anti-templar. Its not that vacuum wouldn't totally screw a guardian, a ranger, or a str dekan, its that if a templar was around it was a waste of a vacuum cooldown not to use it on the templar. That is the exact same thing you are saying about obli.