Games that are more than 30 years old can be remade. The key to a good remake is to not make too many changes that deviate too greatly from the original. Or, if a developer does that, to make the changes optional and give players the choice. Basically a remake should preserve the original with improved fidelity, but also offer any changes as optional content to the player.

Resident Evil (Gamecube/HD) made minimal changes but kept the game mostly the same, utilizing graphical fidelity increases on the base gameplay. I think the remake was done pretty well. It didn't offer anything optional but game remakes were pretty new when it cane out so I don't hold it against Capcom.

In comparison, I have serious concern for Bloober's upcoming Silent Hill 2 remake (aside from the developers obvious subpar history). Ditching the traditional Silent Hill camera to copy RE remakes and the worst Silent Hill games (and not making the over the shoulder perspective optional) is a major change to the stylistic presentation of the game and shifts the focus of gameplay too much onto combat. With such a major change, I can only imagine what other changes Konami is forcing that will destroy it even worse. I mean, Silent Hill Ascension and The Short Message both did mostly well with music and visuals/atmosphere, but the writing was absolutely atrocious in both of them.