There is a need, if you truly enjoyed the movie and would like to enjoy it again in your own home.
I own dvd movies that I've watched many times. Some of them I never saw in the cinema and was happy that they were on dvd so I could purchase them and enjoy them at hom.
I've Watched young guns & goodfellas probably over 100 times so take that!! Sometimes if you go to cinema you might go for a wee wee and miss it so it's better to watch again! Just don't buy them then
Just because you might not like seeing a movie more than once, doesn't mean other people feel the same way.
A lot of movies are good enough to watch a few times. A lot of people love certain movies so much they'll watch them more than ten times after seeing it in the movie theater.
Not only that, but when you buy a DVD you can see all the extras.
The whole point of buying a DVD is so that you can see it again. Just because a person saw it in the cinema doesn't mean they can't enjoy it once, twice or a dozen times more.
I frequently watch movies more than once, and I get something new and different from them each time.