I think attempting to use Swift on a Linux server would be a big nuisance
I beg to differ. Look at Vapor, Kitura & Perfect.
I know Foundation is missing implementations for Linux, but it is not something that makes it a big nuisance IMO.
You can quickly have a setup with Swift on Linux running a simle CRUD app.
Yes it is possible and IBM is the one pushing for it.
However it is still light years behind JEE and Spring features, including parity with existing JDBC drivers.
Also besides instruments on OS X, there are no comparable performance monitoring tools like VisualVM, Mission Control and many others from the JDK vendors.
But as far as I know, Instruments is using tools available already in lldb, clang and dtrace. So building a UI that displays the collected data should be more than possible.
You can quickly have a setup with Swift on Linux running a simle CRUD app.