Separation of duties.
I work in a fairly large IT department for a Healthcare company and for security reasons always having to involve application support or other teams even during development phase can be very aggravating when I have to ask for simple things like server log files. And the process to get to deploy in production is paved with bureaucracy and paperwork and emails that have little to do with anything other than just say, I approve, yet we are supposed to be trying to implement agile.