But somehow I assume that the typical R10 Customer who upgrades from the (stabilized) cheapo kit lens to a 17-50 Tamron would apreciate any aditional VC
I don't disagree with the sentiment. But I do disagree with the title of your post, "The day the
Canon Grinch stole the OS/VC." I had a look at the Sigma lineup for mirrorless, only 5 of their many offerings have OS and they comprise four telephoto zooms starting between 60-150mm and a 500mm prime. None of the lenses being offered in the RF mount have OS. Likewise, Tamron's one RF offering lacks VC in the other mounts. The Tamron 17-50/4 (to which I assume you're referring above) does not have VC, either.
So, why do you conclude that it's the
Canon Grinch that stole stabilization from these lenses? They don't have stabilization for Sony or Nikon, either.