Imagine if you guys were alive before the technology for home video came about, y'all would probably kill yourselves over the prospect of never being able to see your favorite movies again after they stop showing them in theaters.
No, I don't think they take too long. The time span is just right, people actually have an incentive to go see the movie in theaters. If DVDs were released any sooner, lots of people simply wouldn't bother going to the movies when a film's typical theater run would overlap with the DVD release.