There's been an ongoing debate between balanced and unbalanced cables in HiFi as long as I have been involved. And, that's a long time.
I remember spirited debates with Audio Research founder Bill Johnson about it. AR equipment was a long hold out in adding balanced to their products but over time they gave in, and I believe it to be a good thing.
Balanced interconnects sound better than single-ended do. I know, that's perhaps too strong of an opinion, but I have yet to have any prove me wrong.
There's little dispute of the technical advantages when balanced is done right: noise and distortion rejection, 6dB more signal, separation of signal conductors from shield duties.
What many folks perhaps don't think about when mentally dissecting a single-ended cable is that there are only two conductors inside, and one of them is the outer shield. This asymmetry of design, where the hot lead is a solid core, stranded, or other construction, and the return lead is made of aluminum foil or braided/tinned copper, is not ideal. Rather, you'd want both conductors in a properly designed cable to be identical while the outer shield is separate and distinct from the conductors. That construction is only available in a balanced cable.
My question is a simple one. Why do we manufacturers bother keeping the single-ended RCA connectors on our equipment at all?
The answer in PS Audio's case is likely the same as others. Compatability.
But it's a shame.