After playing a lot of WHM, there is nothing more frustrating than my heal going to waste on someone, especially now more than ever since I would use a GCD trying to generate a Lily on you. (and they only work if you heal at least 1hp)
The only proper time I as a healer would appreciate a RDM's heals is if everything is clearly going to crap and people are going to start dying. There are healers because you guys take damage. If you guys didn't take damage, then what's the point of having a healer? Yes, you can heal yourselves, but the point of this thread I can tell is, your party is losing a lot more damage by you healing yourself, rather than having the healer heal you.

If you can squeeze heals in without losing damage, or letting yourself or someone else die, then of course it's not a big deal. I don't think the OP is saying that at all.