I think the "ritual mastery" angle of the dragonmarks makes up for this. As a House Jorasco commoner, I can still learn and use the Remove Affliction ritual. For a random NPC from the street, this is pretty cool and pretty useful, in a setting context.
This also makes the feat useful if I'm not already a healer. Yes, if I am a healer, I'll be using the dragonmark more often, but that makes sense. If I'm not a healer, I still gain a little healing edge, which is exactly the effect I'm looking for.
I think the racial flexibility is potentially more problematic, but as it's only an option and not an actual setting element (e.g.: there are no dragonmarked dragonborn, by defualt), it's a painless feature.
Rituals, baby! I know they're kind of the redheaded stepchild of 4e in a lot of campaigns, but it works well for the flavor of the dragonmark, I think.