The name is short, it's easy to remember, and most importantly, available.
There aren't a lot of words that rhyme with Derek.
Back in the 1980s, instead of cheap store brands, there were generic labels. If you're over 35 or so, maybe you remember the black and white packaging.
Kids are stupid, and sometimes mean. When I was bullied as a kid, this name was the best they could come up with. It wasn't especially hurtful, just annoying and dumb. Much like the kids who picked on me.
They teased me for being a geek. I've embraced my geekiness, so I've embraced the name, too.