From Rich @ Boulder:
The unit doesn't ignore hi-res, but rather plays the hi-res formats that we're guessing are likely to still be around in the future. Sony has abandoned DSD (no new labels are picking it up and others are hanging onto it because manufacturing costs are low enough not to stop), and DVD-A is already dead.
Also, when we were doing testing on SACD/CD mechanisms, for whatever the reason, error rates for those drives were MUCH higher than dedicated CD or data retrieval mechanisms. When DVD reading capability was added, the already high error rates became even worse.
In the end, we had a choice to make: SACD capability with less accurate read capability and no future DVD playback or initial release with CD playback and no SACD capability. When we factored in that SACD likely has a finite life span, it became an easy choice.
We've recently been listening to some brilliant 24/176.4 kHz .WAV tracks from Harmonia Mundi on the unit, as well as some tracks we had mastered from analog master tapes at 24/96, and they're amazing. If I remember correctly (and I may not because it's been a while), SACD has an equivalent data rate of 24/88.2 kHz. I would wager that the 24/176.4 tracks would produce better sound quality against the equivalent SACD track if mastering choices were the same (the discs are available on SACD, though we can't listen through the same source electronics), and the 24/176.4 .WAV file format will be around for a long, long time in the future.