I don't recall any analysis of the Google/Motorola deal pointing to a rationalization like this. I do recall Motorola's CEO announcing on an earnings call that

I don't recall any analysis of the Google/Motorola deal pointing to a rationalization like this. I do recall Motorola's CEO announcing on an earnings call that if Motorola didn't soon find market sucess with Android it would be willing to start suing other Android ODM partners with its patnet portfolio. Given how quickly Google cancelled all its other product lines, and even sold off the cable box and network equipment business, and then finally sold to Lenovo, it seems like it was always clear in retrospect that Google bought Motorola to peaceably unwind without causing a civil war to the whole platform ecosystem they were building. That being said, I think you did very accurately call out the parent comment's reasoning and exactly what's wrong with it in cases like this. When companies are at a deep, deep discount to their market-leading peers there's usually a reason.