I agree it is a bit confusing, but it makes sense if you think about the expected default use case, which is enabling the cloudflare CDN for customers. They expect people to be using their CDN.

I use them for my registrar, because they offer domains at cost and you can’t beat that. But yes, they make it an extra step to use them without using the CDN.

Once you figure it out, it is fairly straightforward, though, and you can’t beat the price.