I would like to add few points: SWR was formed in 2003 and till then the SWR regions were part of SR and SCR which were formed in 1951 and 1966. When SWR was formed in 2003 it didn't had a Double Lane/Electrified section anywhere except the MAS - SBC region. What have the SR and SCR done to this region for the past 50 Years except eating the revenue from them and developing their own states. I agree that SWR is slow in developing infrastructure but its not the fault of SWR alone.
Regarding running of trains, if you want to run train from SBC to north they only have 3 routes available, 1) YNK - GTL which is saturated 2)...
more... YPR - BAY and 3) YPR UBL which are sort of long routes. SWR is left with no other option than to run trains in this route till the YNK - GTL is doubled.