Christ on a cracker. Web browsers don't understand Opa. They understand HTML. They understand CSS. They understand JavaScript.

Who do you want on your team? Someone who understands Opa? Or someone who knows what browsers know, in detail?

If I know only Opa I'm limited to what the Opa developers know about these technologies. I'm limited by what they know. By mastering these technologies I'm only limited by what I can imagine.

Opa is a barrier on my imagination.