That's a pretty broad statement. Any particular reason you feel that way?
I don't like having a per-character limit on how much someone can be healed each day. In the past, the resources for healing were assigned to the source of the healing, not its target. In 4e, they transfered that to the character receiving the healing. I think that was a huge mistake. It puts a finite limit on how much a character can be healed in a day. When the resources are on the healer side, even if the cleric runs out of spells, you can use wands or potions, or find another healer. There is no set limit on healing other than what the party is able to come by in that situation. This gives DMs freedom to extend the workday if needed.
When a player has healing surges, and runs out, you can't heal him anymore - period. He's done. It doesn't matter if you find more potions, if the cleric has more spells, etc. This forces the party to rest for one character's sake. I also think it's bizarre that even divine magic can't heal someone once they're "exhausted." On the contrary, it's when a character doesn't think he can go on, and the cleric gives him the strength to press on, that the cleric has the chance to shine. Instead, with healing surges, he tries to inject divine power into the person and gets an "ERROR - target is out of healing surges."
I also don't like it because it creates a strange disconnect between PC game mechanics and those of NPCs. Only PCs have healing surges. So if I come by a dying villager, can I not heal him? Most DMs would handwave the issue away and say yes, but technically, by the RAW, the answer is no. I'm not suggesting that NPCs should have to use all of the same rules as PCs, but I do think that while they can be built differently, they should still follow the same basic rules. It also means that there is no sacrifice on the part of the PC when healing NPCs. Healing Word is an encounter resource, and since it doesn't "cost" the cleric anything to use it (the only "cost" is paid by the target of the healing), he can go around healing the sick and injured with impunity. The NPC healing thing isn't a huge issue, I'll admit, it just further adds to the disconnect that healing surges cause.
Just to be clear, I like Second Wind. I think PCs should have some ability to recover without a healer. I don't even mind there being an encounter and/or daily limit on that. I just don't like how healing surges put a cap on ALL healing, including magic healing received from other sources.