Back when the line was non-electrified, we had steam locos in the country.
With steam, the issue is active propulsion power is generated only at one wheel and rest of the wheels are rotated by means of crank. This leads to rather poor adhesion figures and less than optimal TE even though they generate substantial amounts of torque. The outcome is that there is a limit to how steep a grade it could ascend. This is how we got reversing lines on both thull and bhor ghat.
It is no wonder mumbai bound...
more... lines were electrified close to a century ago, the ghats are really steep here.
Of course today diesel locos can do the route, but the localities along the railway line may not be too happy about it :)
KR should have been left untouched though, but PiGo wasn't exactly the sharpest tool in the box :D