No, you are incorrect, your reasoning is misguided.
The norm has always been to not sit idly.
If you have time to stand about doing nothing, then that time is better spent doing something. If no healing is necessary, you make it so other things die faster, thus, dealing less damage, and requiring less healing.
I've always been of the opinion that preventing damage is just as important as curing damage, and thus, falls under the umbrella of the healer.
