MI 1 & 2 support several lectures of the story.
Due to Guybrush inability to explain his real age and various weird occurrences, it can be read as a little kid snooping around a theme park. It explains why he has to think that hard before giving his age, why a tshirt would be a treasure given after vanquishing a sword-master, why some areas are closed off with modern looking out of order signs, etc.
It can also be read as a pirate in a weird weird world.
IIRC, the evil laugh of Le-Chuck and his read eyes were added just before the game shipped against Gilbert (and others) wishes.
Curse and subsequent games completely disregard this and quickly brush it off as another trick of LeChuck. This side of the story telling is then totally absent from the various MI sequels (I don't think there was much involvement from the original team in any of the sequels, Gilbert was briefly consulted for the last episodic game but that's it).
So if Gilbert were to make a new MI game, he would naturally like to take the story where he left it.
The thing is that whatever Gilbert thinks about it, the ending of MI2 sucked. MI2 was genuinely scary in places (http://monkeyisland.wikia.com/wiki/Screaming_Chair), and the revelation that it was all a daydream just made everything you've done up to that point feel completely pointless. This put the writers of Curse in a difficult position, and although their solution was a bit awkward, I can't really see that they could have gone forward any other way.
I agree, while I wouldn't say it outright sucked, it was a bit disappointing. In fact, when I played it as a child I literally had no idea what was going on. I guess it was doubly confusing for me because Curse was the first Monkey Island game I played! Perhaps that's why I don't think too hard about it, I love all of the games and readily overlook the inconsistencies in the story.
IIRC, the evil laugh of Le-Chuck and his read eyes were added just before the game shipped against Gilbert (and others) wishes.
Curse and subsequent games completely disregard this and quickly brush it off as another trick of LeChuck. This side of the story telling is then totally absent from the various MI sequels (I don't think there was much involvement from the original team in any of the sequels, Gilbert was briefly consulted for the last episodic game but that's it).
So if Gilbert were to make a new MI game, he would naturally like to take the story where he left it.