Yes, it’s silly to only use one column when you design a website. It’s also fun. It makes you more creative. It’s easier to build.
Arbitrary constraints—constraints for their own sake—are one of my favourite things. I’m encouraged to push creative limits when I am limited in other ways. You will be too.
The next time you design a website, try to use only one column. You’ll have fun. You might be surprised by the creative approaches you find.