I don't think he came off as ungrateful or anything... The whole, "LeBoug SLAMS _____" titles for these quotes of his in interviews are a bit misleading. He felt Transformers 2 (which I've never seen) wasn't as good as Transformers 1 because it tried too hard to be bigger than TF1... While not seeing the movie I can still imagine the problem and him being right.
With Indy he seemed to feel the ideas weren't maybe the greatest, but that it was ultimately his job to make it good because he's the actor, and like you said E, he took the blame for that... How is that slamming Indy? Indy made a ****-ton of money, as I feel sure TF2 did. He just thought some of the stuff in the movies was dumb or the wrong way to go... I thought him swinging with monkeys was utterly stupid and silly, and I thought his feelings were pretty spot-on... though I'd blame Lucas/Speilberg for going with that.
His sword-fighting was equally dumb. It's odd enough that Indy walks around with a whip but he at least incorporates it into his work as a tool... He uses it to climb, swing, etc. Sorta believable right?
Who the **** walks around with a fencing sword in the 1950's? And then Lebouf just happened to be there and having a little fencing experience himself. Talk about forced action sequence. That was f'n horrible. It didn't look bad, but it was stupidly forced trying to give Shia a dazzling "skill" with a weapon like Indy had was all, and it came off horribly I thought.
Swinging with monkeys was simply stupid looking, and an excuse to shoehorn CGI into a chase sequence. How do you blame LeBouf on that? That's all Lucas/Speilberg butt-raping Indiana Jones.
Hopefully if Indy 5 happens, they learn from Indy 4... Part of me thinks they can, and part of me thinks they're so self-absorbed with their technology in films, that they'll want to shoehorn even more in, at the cost of the movie's quality.