Two thoughts on this:
1. I agree that comedy is vastly underrepresented in Oscar history, and that greatly irks me. The reason is that with comedy, laughter solves all arguments. A film either makes people laugh or it doesn't. There is nothing to debate. If you don't laugh at Monty Python and the Holy Grail, I simply pity you and walk away, whereas we could endlessly debate the cinematic merits of Citizen Kane or 2001: A Space Odyssey. For the same reason, critics often dislike comedy too.
2. I believe the Best Picture should win Best Picture, including occasions when the Best Picture is deemed a "blockbuster", or "genre fiction", or "commercial", or whatever. Most of the time, I disagree with what wins. I despise Academy snobbery, and have written about that extensively here, if you're interested.
Oh, and I don't care for The Deer Hunter, to be honest. I'm with the witty critic who wrote that the wedding sequence went on so long, he felt embarrassed he hadn't bought a present.