Hmm I relly don't understand your point.
If you love healing and need Heal items - go there as healer.
If you love tanking and need Tank items - go there as tank.
You can say that you don't have good enough gear to enter raid as healer to start healing. BUT it was same for you with tanking gear before. When you didn't have good enough gear you weren't able to enter queue - so you had to craft, farm rep, farm gold atc. So go farm better gear as healer, queue as healer and roll on healer items. SIMPLY
Your way - to go as tank and set that you will be rolling on healing items - is only way how to get nice items more easier, without hard work and overoll people which did it regular way.