Oh, and another reason they do it is pretty obvious.
What happens every time a film is remade?
The studio re-releases the original on DVD and bulks up their profits by selling a film that sales have dried up on.
Rollerball, Deathrace 2000, Get Carter & The Italian job, among others, all got reissues when the new versions came out, and usually its an ultra special edition that not only attracts those interested in seeing the original after seeing the new one, but also attracts those fans of the original that have either not got round to buying it or are the sort of people who have to have the bells and whistles version.
