You don't seem to have a very high opinion of your people!

Becoming more agile than you are now entails learning skills you don't have now. This could include your Scrum team members who used to call themselves "testers" learning how they can help on the first day of the Sprint, your "coders" learning to collaborate, and everyone learning there's a fruitful gray area between black box testing and white box testing.

Scrum's not for everyone, and some of them may leave. But most people I've met in this business are interested in learning new ways of working.

--mj