Should they? No.
Would they? Yes.
Film makers, directors, producers, screen writers, etc, they all think they can do it bigger & better. A lot of times they want to make an easy name for themselves by revamping an existing idea, sometimes they just want to pay tribute in some weird self-centered way.
There are some cases where a remake would be justified, but only for tech advancement reasons. Take the recent remake, Clash of the Titans. The original was great but obviously claymation & puppets can only convey so much. Modern cgi turned it into a spectacular showcase; however, the story alterations & poor casting weighed the remake down. The remake was justified, but executed poorly.
Remakes can be done very well if they put the effort into it. But Hollywood is all about money, big & fast money, so remakes tend to suck; they rely on a lot of flash & glitter and the name itself to make the money, they could care less how good it actually is.
