Having worked in IT for over 30 years and having worked for Fortune 100 companies, I have never see it work this way.
I have seen C-Level executives come in with a great new idea about how they were going to save the company millions by changing everybody's desktop to BYOD. Thus eliminating the need for the company to buy, maintain, and repair desktop systems. That lasted all of 30 days before security and legal come down on him.
In today's corporate IT environment we have to meet regulations. They may be something as simple as SOX or as complex as GxP. In those regulatory environments having an open network where everyone can bring in any piece of equipment and plug it is becomes a major problem. As such there are policies in place, there is training, there are physical restrictions, and there are software enforced restrictions.
I am currently working for a rather large Aerospace company that was recently acquired by another company. The new management seem to have problems understanding that having everyone on one network is an issue. The new company has locations in China, Taiwan, and Korea. The company they bought handles government contracts from everyday items to items that are classified. It is a violation of federal law to have foreign nationals on our network because of the government contracts we have.
So, from a management point of view I am sure that having everyone able to bring in whatever they want and connect it sounds great. however in the real world IT and IT Security are the ones that have to, not only manage them, but they also work to mitigate the legal risk. Some of the more important jobs in IT, is to protect the company's digital assets. Including understanding the laws, regulations, requirements, and licensing of the products the company uses.