I wouldn't be so sure. They could have a much more advanced idea of what life is, and life could have deep meaning to them, they might seek to keep their biological selves in tact and use machines only as tools. I know that's how I would roll, and I'd raise my kids that way, a group of beings like that could spawn a nation down the road with a rule like that. Or with their understanding of life and computation and intelligence and the universe, it could just be self evident to them: your form follows your function, if you change your form you change your function and you're no longer you. Sending robots, sure, becoming robots, I think you're bound to meet at least as many that don't as that do.

One meaning of the word simple is naive and/or unintelligent, so depending on your attitude, simple might be a perfectly good word to use here.