for quite some time now WR has been operating mega blocks at night (mostly after 22:00) so the allegation that it affects traveling on sundays isn't completely right.
Secondly, failures on line happen due to multitude of reasons: rake breaking down, problem with OHE, track failure etc. of these track failures are very rare, thanks to periodic maintenance during blocks. the issue with OHE will take time to go away as it is mostly due to the older, rigid type conductors being used. Its the last type of failure i.e. breakdown of rakes that is the real headache. even the normal, non-rail fan type people in Mumbai know that BHEL rakes have high amount of failures.