I feel everyone is looking at it wrong. Any class can have cure or sacrafice, as well as second wind, bloodbath. Any class can have Siphon MP, radiance, and damnation. So there is a list of abilities to heal YOURSELF, and abilities to get the TP/MP to do it. No need to depend 100% on mages to heal. Similar to how aggro management isn't 1oo% the tanks resposability.

Animity managment, Hit Point managment, Damage Dealing, Debuffing, buffing is every classes job. Every class can do some of everything mentioned. Maybe the problem isn't the system in play, its that you're not playing the system.