Couldn't agree with you more. I was so tired of mopey/emo/dark/miserable Spidey by the second movie that I didn't even bother to watch the third one. It was like he was turning into a different kind of character.
I think it's a problem these days, comic characters and everything about them have to be SO serious. It bothered me in the last Batman movie too. It was like "Oh yeah, they've made all those colorful, silly Batman movies, let's show them how dark and serious the man really is. Batman is serious, people! Pay attention, he's SO serious!"; but sometimes too much seriousness can turn into a joke.
That said...
Again I agree. I have nothing against a bit of fun in a movie like Wolverine. Actually, I loved Logan's sarcastic lines, as when he answers Bobby's parents in X2, or scenes like the cat one, or in the mansion's kitchen with Bobby. I always thought that Logan has some kind of black, sarcastic sense of humor that I think would fit the movie nicely.
Now, my problem isn't the humor, my problem is a Deadpool-style humor. I find the character annoying as hell with his non-stop "clever" remarks. I don't find him funny at all, not even an interesting character. Really, I would hate to see him in "Wolverine".
That was a great scene, and there were other "grumpy/sarcastic Logan" funny moments in the trilogy too. Sometimes just seeing the grumpy look on his face would make me laugh!