Sometimes remakes are successful, sometimes they are not. I suppose it depends on what you're trying to achieve with the remake. There's manifestly little point in doing a beat-for-beat copy of the original if you're going for artistic merit points, so you ought to be aiming for at least *some* sort of fresh take. A new angle, a different emphasis on themes, a new interpretation of the characters, or whatever. The 1946 Great Expectations, that got rave reviews here, wasn't the first adaptation of that book on the screen, so is clearly a "remake", and a thumping good one at that. Or you have the 1995 Pride and Prejudice with Jennifer Ehle and Colin Firth, that is by far superior in most people's eyes to every adaptation that came before it (and certainly, to my eyes, than the most famous adaption that succeeded it, 2005's film with Keira Knightley).
Of course, if you have something new to tell, then maybe that "new" stuff won't work -- at least not for everybody. But we can perhaps get too invested in preserving the integrity of the original, so I don't think there's a harm in trying. As long as your aim is to find something new to do, then we have to expect that sometimes it'll fail.
The real scandals are the "obvious cash grab" remakes -- see, most recently, the live-action Disney remakes of Mulan, Beauty and the Beast, the Lion King, Aladdin, etc., most of which are pale imitations of the original and, inasmuch as they *do* deviate, do so in ways that seem to misunderstand the source material. Then again, the Lion King remake pulled in like $1.5 billion in ticket sales, so it probably succeeded at its main aim...