If light rail was really needed there would be an abundance of paying riders clamoring for the service and private enterprise would move in to meet the need.
Too many cities and other government agencies want light rail because they believe it puts them on the map as a more significant urban center.
And the large sums of money involved open the doors for plenty of graft, chicanery and sweetheart contracts resulting in generous contributions coming back to the politicians.
Every light rail system is built with politicians promising profitability right around the corner.
But they never seem to get to the corner.
If light rail was really needed there would be an abundance of paying riders clamoring for the service and private enterprise would move in to meet the need.
Interestingly, that sentence was actually operative about 100 years ago...
Government will never allow privately-operated passenger rail of any kind. It was the first target of leftists going back about 100 years; Woodrow Wilson even nationalized all the railroads at one point, under the USRA.