Oftentimes, the decisions admins make are determined by the needs of management of fellow employees.

I have on frequent occasions mouthed words along these lines: "It's a bad idea to do it that way, but I can see how it would be much cheaper, efficient or easier to teach employees, so I will tell you the best way to do this bad thing."

You can carefully set up the best security possible, but the instant that a client or bigwig is waiting on something because of it, credentials will be shared and you or other employees may be ordered to share them.

It's just how it is.