The issue of "where's the money coming from" aside, it actually makes good sense to electrify rail commuter lines.
Electric locomotives will last at least twice as long as a diesel engine. Easier to maintain, fewer moving parts.
Or... go to self-powered "MU" (multiple-unit) cars, no engine needed.
Electric engines accelerate faster, and pack more horsepower-per-unit than a diesel.
The initial build costs are very high, however. Poles, substations, wire, new signaling (if the existing system isn't compatible), and of course the rolling stock. But electric traction pays off in the long run.
I ran these for more than 30 years:
(916 when newer -- my favorite)
(916 in later years)
30+ years old, and still could get it done with ease.
Not many passenger diesels (any?) that can do that!
BTW, I have no problems with Mrs. Chao's decision regarding funding.
But for commuter trains, nothing beats electric power.