The Fuel System design harkens back to certification requirements and the ability to dump fuel....as I recall it being told by a Factory Pilot doing 105/117 Training....with the 135/145 being follow-on designs.
We had major concerns over the Fuel System design when working up an IFR EMS Program for Duluth, Minnesota back in the late 80's...early 90's.
In theory it is a fine system....but does have some quirks that can bite you in the Butt if abnormal situations crop up at the wrong time and place. Putting the Pump Switches up on t he Overhead Panel seems to be a step backwards re safety in my view....they would have been better to leave them on the center console where you can see the things in the Dark and while wearing NVG's.