Everyone involved is to blame (including management), but it is an engineer somewhere that actually makes these things. Devices don't magically start spying because a business person makes a deal. The data doesn't magically end up in the hands of their 500 partners. There are large datastores to scale and integrations that require work to build.
And even if they're never held accountable (I expect they won't be), you should at least be acknowledging that they have no ethics and shunning them, not defending them for actually being the ones that built surveillance hellworld.
First, no single engineer that will completely implement this "spying feature". A hardware engineer knows how to put the mic inside the TV, the FW engineer knows how to write driver for application to get mic data, the application knows how use the pre-trained ML blob to process the data and send the result to Cloud. At that level, no one really knows what happening any more.
Can they make educated guess what is happening? yes, but still, it's just a guess.
There would be "alignment meeting" accross the various team, but trust me, they would never use the word "spying" in any slides.