For example, if a question has a hint of Linux in it it gets booted over to U&L, if it has a hint of databases in it it gets booted to DBA and if you're doing any programming/scripting in your role as a sysadmin and want to ask it it goes to SO.
Where do you get those examples from? They're fundamentally incorrect, and therefore, the conclusions you draw from them are wrong as well. Server Fault actually has a huge scope, so much so, that there aren't member capable of answering a lot of the more specialized questions we'd like to see answers on.
As a result of that, a frequent reason for migration isn't so much that it doesn't belong on Server Fault, but that it is more likely to get a better answer somewhere else. As a result of the overlap between SE sites, that's unavoidable, and there's often no one place a question "should" be asked.
Feel free to ask it in one place, and have it migrated if it doesn't get enough attention or any good answers in one place, or ask related questions on different sites.