Illogical request and impractical for the manufacturers. The DD tagged on unit isn't a full-featured audio processor and it is really a single format decoder. There are HDMI audio extractors/decoders/de-embedders (One example: http://www.atlona.com/pdf/manuals/AT-HD570_manual_v2.pdf
) which do similar but they aren't audio processors.
Bear in mind also:
1. By the same logic, you don't need input switching or video scaling/processing on the TV, so would you ask for a TV manufacturer to make one 'barebone'?
2. An audio processor should take care of other legacy inputs, SPDIF and analogue. Not everyone is using HDMI.
3. If cost cutting isn't a concern, then what is? Complicated in what sense? Switching is detrimental to SQ?
4. What if the only audio input is faulty, you have nothing else to fall back on.
5. Not everyone who uses an audio processor necessarily uses or wants to use a video processor or uses it for switching. A video processor remembers settings per input, likewise an audio processor can do the same and some might prefer that.
6. Audio processor is already very niche, it just doesn't make sense to make one with one input, one with two inputs, one with three inputs in different combinations just to cater for a few customer's specific demands.
Actually the Meridian processor is something like that, with its one proprietary input which needs another Meridian unit to take in HDMI inputs and output in its proprietary encrypted format. It is more complicated, not less, and the first unit still does input switching.