Electrify to Swansea

The recent UK government decision to electrify the Great Western route from London to South Wales has one major flaw.  It has been decided to electrify only as far as the Welsh capital, Cardiff.  The main line and 65% of the trains that use it goes on to Swansea.  The division of traction at Cardiff is a mistake.  The short-terms costs of taking the wires on to Swansea must outweigh the lifetime costs of mixing traction over the route.  Come on you guys, do the sums!