Have seen several stories on the M-N problem over the last few days.
Issues discussed in seem to include:

* 2 main feeders to the line. The one near New Haven was taken down for repairs
figuring the other one from Con Ed could handle it. Maybe ended up overloaded?

* As with much of the NEC (except N of New Haven), the electrification dates from
the 1930s. Even with constant maintenance things work only so long.

* Con Ed - 'nuf said?

* Without electrification, the railroad would not have continued to function all
these years. As demonstrated now, you can't handle the schedules with diesels.
High Speed (over 120mph or so) trains need more power than it's practical to produce
with diesels.

Could go on into lesser things like moving the emissions to a power plant (more easily controlled), which was not an issue when the line was electrified (operating performance was the big one). That stuff like this can shut down the railroad is less an issue with the concept of electrification than it is with lack of redundancy and the age of everything.