I do think DSG/PDK sounds like something I'd want on a street car where you get all the advantages and feel of a manual tranny
No matter how often you say this, it isn't true. You do NOT get the same "feel" when you're not modulating the clutch yourself. Sure, it's not objectively better than a DSG (not faster, not more fuel efficient, not more convenient), but it is absolutely not true that you get the same "feel" with a DSG that you do with a traditional manual.
Audi is all about advantage through technology, why would they want to go retro when DSG is faster and better by any measurable factor?
They offer a traditional manual in a B7 RS4, a B8 S4, and the R8 supercar (both the V8 and the V10). Given that context, the question for me isn't "why would they offer a manual in the RS5," but "why
wouldn't they?" It's not like the RS5 is
more performance-oriented than the R8 V10, right?