I understand the frustration but...
The average player is paying no attention to this. There will still be players healing when Dawntrail is released and Duty Support to use if queue times are long. The only stumbling block would be the trials, assuming SE isn't giving them the level 89 trial treatment.
For the sake of discussion, let's assume you could get the average player to join in on the strike. If healers truly aren't needed in content, why would a strike even get noticed? Players can pre-form their parties to avoid the Duty Finder role restrictions after all.
Good luck to you. I'll still be healing for Dawntrail because most of those I play with can't make it through the content without a healer and I'm not going to screw over their game experience just because the developers can't figure out how to create a satisfying healer experience for the high end crowd. I do genuinely sympathize but having a good time with my friends is more of a priority for me.
Get your tanks to stop using their active defensive and healing abilities. I was healing a tank that used 0 defensives through Tower of Zot the other night. Can't remember the last time I had to use so many GCD heals.