Nope. It's also not true that it was because Betamax was too late as many claim. Betamax came out in 1975 and VHS in 1976.So Betamax actually had a slight head start.

The reason Betamax lost was that Sony had exclusive rights to Betamax, and they tried to monopolize the market.VHS was a way more open standard all could use, which lead to the obvious result that everybody that made video-recorders made VHS.With the way better availability and more competition on VHS recorders, and VHS being cheaper to make to begin with, prices on VHS were way more more competitive. This was a significant factor because video recorders were very expensive early on.The tapes were also cheaper for VHS, which probably was a factor too.

This of course led to VHS also being by far the preferred format for video shops, as there was a bigger market for VHS videos.Some claim that the way wider availability of VHS movies in video shops was a factor too, but this was IMO more a result of more people already owning VHS videos when video shops became popular. And if you loaned/rented a moviebox with your videos, those were also always VHS, for the obvious reason that they were way cheaper for the shop.

So in short, it was all about price and availability, because that shit was expensive early on, and I bet the porn industry chose VHS for the exact same reason everybody else did. It was cheaper for them, and being cheaper for consumers too, you could reach a wider audience, meaning you could make more money.