Thanks ...and point taken.
It certainly is not a realistic although very render cost effective method of showing fire/flames in a scene.
I'd say your way of doing it is a more realistic approach. Since the brightest spot in a flame usually is pure white which doesn't come out very well in my render. That is however something that could be done easily inside photo manipulation software.
Now it's for everyone else to decide what's more important - render time vs. realism - somehow that seems to be always the question though