You just summed up exactly what I said.
Me:
"The mixed 32/64 environments started after G5 release (10.3 had 64-bit addressing "bridge" of sorts but no 64-bit apps) and didn't finalize until Snow Leopard."
And you:
"When the G5 was released, Apple did a special G5 only release of OS X Panther. It featured a 36 bit memory addressing (which could address way more memory than the G5 could max out at), and features that allowed an application to take advantage of 64 bit memory and addressing."
Saying that it does not work that way "at all" is a little much. Where is the division?
"...and features that allowed an application to take advantage of 64 bit memory and addressing"
This was my "bridge" you called it "features".
I think my distinction is that apps could use the 64 bit features. So yes, you could have 64 bit apps at launch with the G5. XCode grew a 64 bit PowerPC compile switch and everything.
Most developers didn't do it *cough*Adobe*cough* but they were perfectly able to. Developer laziness in adopting 64 bit is entirely different than 64 bit apps not being possible.