For some reason sitcoms still believe we need to be told when to laugh. To prove that the laugh track is completely useless and outdated, we took a funny show without one, put one in, and the results were surprising.
A laugh track actually made this funny scene in Arrested Development less funny. People with even a remote sense of humor can recognize a funny situation, and it really is an insult to intelligence to be encouraged and nudged by an artificial track to be told when to laugh. It serves as a crutch for shows that aren't funny enough on their own, as proven by YouTube videos where they take the laugh track out of sitcoms and you see just how boring (and creepy) the shows are.
So why didn't the laugh track die a (deservedly) swift death in the late 90s? Because no matter what there will be shows that aren't funny enough to stand on their own, with viewers that aren't smart enough to think on their own. (CBS and ABC, I'm looking in your direction!)
And just for reference, here's the original scene with no laugh track: