> The article still has no answer on why it is so difficult to actually get a Sonos to play nice with the two interfaces supplied by Amazon and Google
This is answered in the article. That's what GhettoMaestro is talking about. Specifically - Google said that it would pull Assistant support if Sonos added support to simultaneously listen for Alexa. That's the answer as to why they don't support 2 competing interfaces. Not a technical decision - but looks more like a business decision from Google.
Even if you disregard bullying - this seems like a way for Google to assert exclusivity.
>APIs that every consumer can hookup with IFTTT
This only works if the API is open enough to use. I somehow don't think Amazon Alexa and Google Assistant agreements with third-parties would support that.