Everyone on this show was told they were doing Shakespeare, so they hammed it up like crazy, in hopes of winning the Shakespeare Acting Trophy an getting to meet Patrick Stewart. One time the guy who played Snarf questioned it, and the director was like "THIS IS WHAT SHAKESPEARE IS. YOU DON'T KNOW! YOU WEREN'T THERE!" Snarf couldn't argue with that logic.
What's funny is how Patrick Stewart really seems to like the toons these days. He's basically a regular cast member on American Dad. I wonder if he secretly wanted to be on Thundercats. They should've milked that a lot more; Star Trek TNG episodes were way more convoluted than the things the head Thunder Cat Guy complained about all the time.