I understand what you are saying but I feel you are missing a few points:
- Your first comment referenced the demise of Sonos if they didn't address specific minor complaints from customers not the ability of other organisations to compete with Sonos, hence my comment about Google Assistant;
- I agree that if Amazon decided to target the high end multi room audio market their R&D budget would be much bigger than Sonos could respond to but the strategy of Sonos is to move their product line to include multiple AI's from Amazon & Google and maybe Microsoft - something that I suspect that any of those three organisations would be unable to achieve (hence a good defence against this approach);
- At present, Amazon's strategy appears to be about market saturation with Alexa, and at this time selling hardware at cost, so that it is the 'go to' voice control solution. I see no logic in them focusing upon a (from a Amazon perspective) niche market that Sonos currently occupy;
- A lot of the issues that people are complaining about on the forums are because Amazon don't allow 3rd parties, like Sonos, to provide that functionality, indeed not even all of the Amazon product line offers 100% of the Aleza device functionality.