Earlier quoted context omitted.
If you every played the first two Monkey Island games, and understand the lore behind that, then the ending is pretty good. Thimbleweed park, in many way, was a spiritual successor to Monkey Island 2 that Gilbert couldn't make for IP reasons back in the day. With at in mind, I enjoyed the ending. That said, Monkey Island 2 got a lot of criticism for its ending too...
Oh and if you really love that dumb, sophomoric ending, you can also get Return to Monkey Island, which is yet another game Gilbert ruined with this tired trope. And that's why Curse of Monkey Island is and will always remain the best MI game.
Isn't it a bit different with Return to Monkey Island? The story is told to kids by Guybrush and Guybrush being an unreliable narrator, it's uncertain how much of the story was real or an imagination by him.
The last scene though shows that something real somewhat similar to what Guybrush told did happen.
Also it completely retcons the ending of Monkey Island 2.