Ok, I've calmed down.
I'm starting to think there weren't many people that used/ knew how to use, the old technique, so I can see that the decision to drop it (quietly) was not arrogant, I shouldn't of said that.
I also assumed before that other unbiased renders could handle transparent polyselections, but now I'm not sure they can (tried to google it).
For Archviz, for glass facades, esp wonky shaped facades, it really is needed. Most archviz artists won't be able to uv map a rhino cad file of a modern wonky building.
For flat glass panels, my preferred option is to map a channel from the side, which passes through the front face of the glass. The map is a blank white rectangle with tiling off
Here is an example for a bump map, To get a coating on just the front face i can filter out this channel with a backface material (of clear glass)