The crux of my complaint isn't the HomePod itself. It might be a marvelous piece of engineering that gets the best sound out of it's source material better than anything near it's price range. But Apple has decided that this hardware's primary purpose is to push their subscription service. If the entire reason for existence of this product, which the backstory that Apple has released say it is, was to get the best sound in a small package then allow people to connect their best music sources to the device. No artificial limitations. Because the data input for this is wifi, so the packet layout and information standards have been in place for years. No one company controls implementation of how data needs to be formatted to use ethernet or wifi. Opening it up would have no effect on how good of an AI assistant Siri is, either. There isn't a hardware reason** that Apple can't allow any and every digital music source access to the HomePod, and it wouldn't take a redesign of the hardware to allow it. This software limitation is a marketing decision to sell their streaming service, period.
Free the HomePod.
**There may be licensing (legal) reasons, but then the fault lies with that company and not Apple.