While I believe that industry experience can, indeed, be a huge help, I believe it should be "nice to have" rather than a requirement when it comes to DBA's and "Ninja" SQL Developers. Both of those types will quickly ramp up on just about any industry. It takes a much longer time for someone with industry experience to become an excellent DBA or "Ninja" SQL Developer.

The real fact of the matter is, I usually ignore the "must haves" on those types of job requests... it's usually just wishful thinking on the part of the client or something that HR said they have to include. For example, tell me why you think a DBA needs to have a Master's degree in rocket science to handle an accounting database for a health insurance company.