Casablanca has been remade 'A Night at Casablanca' just a few years after the original.
Many films considered classics are themselves remakes - The Thing, The Man who Knew Too Much, Scarface, Apocalypse Now (arguable), His Girl Friday, Wizard of Oz and Heat spring to mind.
Many remakes are...
I think people are lazy in their dismissal of remakes. There are many classics that are themselves remakes, either regular remakes or 'reimaginings' (such as samurai films reworked as westerns).
For me, it comes down to vision. If there is a reason you're remaking it that goes beyond 'well...