"It was early adoption of the VHS format by pornographers that lead ultimately to its adoption and the "death" of BetaMax." -

That part is partly true, although it omits V2000, and also omits the fact that "legitimate" films by which in this case I mean films conforming to MPAA standards or UK cinema censorship certificated standards in VHS format largely drove much of VHS market penetration (no pun intended). In the UK it was the "video nasties" (think "Last House on the Left, Cannibal Apocalypse, Cannibal Ferox and a whole range of films that never quite aspired to the status of Tobe Hooper's classic "Texas Chainsaw Massacre") that also drove the market.

I question the analysis that Betamax was the studios' captive format: it was the attempted fallguy in the US "Betamax" case that was the forerunner of the legal arguments that have since swung the other way for Pirate Bay, Napster, Grokster, Limewire, etc.

It is however true that the availability of otherwise prohibited material did much to drive the early "video market" and also the internet. But the fact that money has been made that way is not necessarily a justification.