As with most thing NYC transit it's a mix. It would have been a huge disruption to people travelling into the city doubling commute times. On the other hand not

As with most thing NYC transit it's a mix. It would have been a huge disruption to people travelling into the city doubling commute times. On the other hand not shutting down the line means very important repairs have to be jammed into nights and weekends. Some repairs just won't be possible within that time so it'll have to get fixed later when the damage may have worsened.