Even the first Cleric I ever made, a 28pt build, didn't need a party to get anything done outside of a raid. So I'm failing to see how a soloing Divine (Clr/Fvs/Druid) is an issue in your example. Even taking it to a personal level and looking at my own remaining divines... they still don't need anyone. Yet running with groups is something that can be fun. Healing groups was never the problem. Being able to provide healing without heavy resource usage and varying degrees of frustration become dependent upon who is present in the group.
Epic levels flip the script for a lot of divines. Hyperinflated saves and increased spell resistance prove to be too much of an obstacle for the vast majority of players in that range. And though the enhancement pass allows some possibilities for restoring some of what was taken, the end result remains to be seen.