Well, they are certainly immature and tasteless, but with the combination of the stress of being a chem major, and the fumes in the lab, we make alot of stupid jokes. And then there is the age and maturity factor of most undergrads.
But chemists don't always grow out of it. There is a reaction called the Cope reaction. Many Copes are degenerate reactions. Cope was apparently a real ass, this led to a number of papers being published about these reactions solely to have the words "degenerate Cope" in the title.