Forcing affordable housing inclusion in the downtown areas near rail stops seems counter-intuitive to needing the rail in the first place. 

Naturally, housing demand pushes outward from the urban core in search of affordability. The problem it creates, also naturally, is increased traffic congestion. The rail was meant to address that problem.

If you force affordable housing inclusion surrounding urban rail stops, you're telling people that the rail wasn't really necessary because zoning would have solved everything.

And if you're relying on property and hotel taxes to fund the rail, wouldn't you want to maximize those revenue streams by getting developers to invest in expensive developments surrounding urban rail stops?