Developers can make fine admins, they just usually don't. It comes down to human nature and it's because they're likely to make changes or fix things on the fly, with eternal optimism, and not necessarily follow production rules to ensure a stable system.

If you minimize rights, and can enforce your production rules, then this would be ok. The big thing here might be that a better auditing system would need to be in place to ensure that rules were being followed and short-cuts for expediency's sake, weren't being taken.