No need for conspiracies - see for example the presentations from T-Mobile to nanog: https://pc.nanog.org/static/published/meetings/NANOG73/1645/... and https://www.internetsociety.org/resources/deploy360/2014/cas..., just for two examples after thirty seconds of googling.

Comcast has had ipv6 support rolled out for some time now. I don’t know why you don’t see it.