If it was train lines including rail ownership I can see why they would want to drop out. Logistically that's a nightmare unless it's totally private.
Then again around here the rail lines are mostly owned by grain/grass farmer groups who ship product by rail and can load from their farm directly. Passenger lines that share the rails wait for those trains.
GE was a big player in the diesel-electric locomotive market, starting with the GE Universal series, then the Dash 7, Dash 8, Dash 9, and Evolution. The division was sold off at some point there, I think before the Evolution. Back in the earliest days the engines themselves were provided by companies such as Cummins but in the 60s GE started building its own prime movers.
As stated by another post, they built the trains but didn't own the track.
However, I'm not sure your conclusion about owning railroads is a nightmare is true. Berkshire Hathaway (Warren Buffet's company) bought Norfolk Southern in 2007 and it's done fairly well since. My understanding is that these are relatively stable businesses because the barrier to entry is large enough to stifle competition.
Then again around here the rail lines are mostly owned by grain/grass farmer groups who ship product by rail and can load from their farm directly. Passenger lines that share the rails wait for those trains.