Actually, I'd only call The Grinch a remake, since it actually uses a secondary source for material (the Chuck Jones cartoon's music, as well as some other themes). The others are based specifically off the book, and technically not a remake... no more so than a Dracula film based on the book is a remake of the Bella Legousi one. I'm sure the Lorax movie couldn't be any further than the original Depatie Freling cartoon.
In fact, it seems everyone's completely ignorant of those ever existing. Though the Angry Beavers parody of Cat in the Hat manages to make reference to that cartoon. But then again, everyone's seen How the Grinch Stole Christmas... no one's seen (or remembers) Halloween is Grinch Night.
But while I do think materialistic Whos misses the point of the book, it manages to make a point all its own. The book and special have the Grinch stealing the Who's joy out of just being annoyed with it, the movie Grinch was just disgusted at the blatant hypocracy and greed of the Whos... and for a Christmas movie, that's a nice point to make. Still, the Jim Carrey bouncing took away from whatever the movie was supposed to be. But I kinda enjoyed it because I wasn't completely annoyed by him when I saw it.
As for the Lorax, I'll see a good percentage of kid's CGI movies, just not all of them. I was pleasantly surprised by Igor (though I hated how happy the ending was) and I quite enjoyed Despicable Me... but Lorax just doesn't look like it offers anything special at all. Just a plasticky, throwaway environmental message that will no doubt tick off a bunch of Neo-Con squawking heads, but offer no substance or open any eyes that refuse to be opened. The original book and animated cartoon were at least sincere about it.