@ebontoyan
An American in Paris had one of the worst books of the season. The was essentially no real driving force behind the plot, let alone having any character development. An American in Paris may have been one of the prettiest shows to look at this season, but that does not make it the best musical. If you are going to have sour grapes over an in your opinion "boring" artistic musical winning over an "entertaining" "commercial" musical, I would not use An American in Paris as your example. If anything I were in your shoes I would be more upset over Something Rotten not winning, than An American in Paris, which is a truly solid musical all around (score, book, production).
Fun Home may not have a "plot" but that is because it is a memory play. Big Alison is going through a box of her father's stuff as she begins sketching out what will be her memoir Fun Home. When she takes an item out of the box, she is immediately taken back in time. Once she starts to examine the past she wants to discover why her father stayed in the closet leading to his suicide. Since he killed himself 3 months after she came out, she feels her sexuality played a major role in his demise.
It is a very unique plot structure, especially for a musical. The plot may not seem entertaining on paper, but its the performances in conjunction with the in the round staging that make the show soar. If you see the show and disagree, that is fine, but you cannot solely base your opinion on the cast recording.
I will concede about ONCE winning, as it was one of the most boring pieces of theater I have ever sat through. It was like watching paint dry on a Picasso, beautiful but boring. The show had no plot:
Boy meets girl, Boy and girl fall in love, Boy finds out girl is married with a son, girl finds out boy has a girl friend in America, boy and girl make a song together.
Did it deserve to win over the more commercial yet equally successful Newsies, in my opinion no, but I am not a Tony Voter.
Fun Home on the other hand is truly great musical, that we won't wonder why it was successful 20+ years from now when it is revived, compared to An American in Paris, which only works because of the production and not the musical itself.