One of my toons is a healbot/nannybot, i don't play it much anymore, though after update 5 with a re-spec for radiant servant that may change.
For a long time i enjoyed the nannybot role, but over time that faded, and it became more of a chore then anything, keeping a glut of low ac, low con, low dr toons alive through quests my healzbot could easily solo as i discovered over time what an effective spell killer my 'healbot' actually was.
Then i rolled out a 2monk/18fvs, and rediscovered the 'healer' class. Able to melee 'effectivley' with top level quest bosses, able to solo nearly every quest in the game, killing with spells, killing with scimi's (valenar elf enhancement line on mine

, killing with handwraps, self buffing, and able to primary heal raids for my guild whenever we needed it, it became my pride and joy, wearing more raid loot then you can throw a stick at, re-defining for me my expectations of 'healers' when playing my other characters (i have more then a few capped toons, playing most every class in the game, i happen to love the game).
One of my most enjoyable playing sessions recently was my fvs and a group of guild fvs players doing a tour of amrath, all in full melee mode, we ate that place alive, with 32 minute bastion of power being a high point for me (i have a love/hate relationship with all maralith's in the game :P).
My point is this, pidgeon holing classes is a sure sign of lack of experience, all classes have some access to healing in one way or another, and more experienced players will build their toons with a certain degree of independance inherant in the build (some will even sacrifice a little bit of dps to be survivable! shock horror).
If someone enjoys being a pure healbot, great, they have a definite role to play in the game, but don't think that's all they can or should do, because it's just not the truth, it's an opinion, and a poorly informed one at that.
Regards
Ghallanda : Coitfu, Coitrippr, Coithealz, Coittimeh, Coitburner, Coitfulff, Luciforge Son of Coit : Revelationz