The intent behind the remakes of Grim Fandango, Day of the Tentacle, and Full Throttle comes from a spirit of preservationism more than anything. The idea was to make these games easily purchasable and playable by modern audiences while keeping as much of the original games intact as possible. So you get things like cleaner audio, uprezzed graphics, simplified controls, and so-on, but nothing that radically changes the games.
As someone who has the original game CDs and played through each of those games at least 10 times over the years, the BEST part of these remasters, IMO, is the added developer commentary. I really, really enjoyed playing through the Monkey Island and Grim Fandango remakes and hearing Tim and crew's thoughts, remembrances, jokes, etc around the development and production of the games, the music, the characters, etc. Really added something new and special to the playthroughs of games that I know like the back of my hand, like old friends.
Graphics aside, the revamped input options alone justify the remaster IMO. They got a lot of things right with the original but tank controls were not one of them.
I still wish the graphics were better, it looks like Grim Fandango and Day of the Tentacle don't have much improvement in graphics department, so I'm afraid Full Throttle will be similar disappointment to me.
Comparing that to remakes of Secret of the Monkey Island[1] or Bionic Commando Rearmed[2] (different genre) it looks poor. It feels like LucasArt (and actually Disney) are simply going for making easy money on people who are nostalgic about these games with as little investment as they can.
It was certainly different, but I wouldn't say the original art style was 'destroyed' due to the fact the at any time in the game you can switch back to the original style. It's not exactly destroyed if its RIGHT THERE.
I think with DotT there is less room for that kind of art upheaval though, because, frankly, the art already looks good. It still holds up very well today, expecially if you run in SCUMMVM in turn on some graphics filters.