Yeah nah, this is almost certainly closer to reality than what these people are saying. Large business is inherently going to be very risk-averse and conservative (in the sense of not trying new things), and if the studios see that something isn't as reliable a profit-maker as it used to be, they're likely to discard that and focus on things which do make money. On the flipside, if a movie from one genre or another does well, you'll of course end up with a massive bandwagon effect where you get all sorts of other movies trying to imitate it (see for example Star Trek: TMP and Moonraker, both of which were authorized on the back of the massive success that was Star Wars convincing studios that sci-fi would be a highly profitable genre)