There are different schools of thought about this. The traditional school of thought is that for people to go to the movies, go to the trouble of parking their cars, and pay $12 or more for a ticket, the film cannot at the same time be available for less at the push of a button in their own living room. That's one school of thought. Today, for example, if a film does go out simultaneously on other platforms, Canada's largest exhibitor, Cineplex, won't play it. They will only play films that delay their digital and television release.
The other school of thought is the more the merrier, and if a film is available in every single way at the same time, they will attract different crowds, different audiences, and different segments of the population, and people who wouldn't go to the theatre anyway would see the film.
I'm probably more in the traditional camp until persuaded otherwise.