Putting high density and moderate income housing next to commuter rail stations should be a no brainer. Amazing that so many people are sputtering about it.
Suspecting that they’ll force single family homes out is the issue.
Frankly, unless the population density is already high and geography already constrained so that you can serve a large number of people with minimal infrastructure things like local commuter trains shouldn’t even be considered.
They certainly shouldn’t be developed into the excuse to force higher population density where it doesn’t occur on its own.
Look up Pruitt-Igoe for why this is a bad idea:
The Wendell O. Pruitt Homes and William Igoe Apartments, known together as Pruitt-Igoe, were joint urban housing projects first occupied in 1954 in the U.S. city of St. Louis, Missouri. Living conditions in Pruitt–Igoe began to decline soon after completion in 1956. By the late 1960s, the complex had become internationally infamous for its poverty, crime, and racial segregation. All 33 buildings were demolished with explosives in the mid-1970s, and the project has become an icon of failure of urban renewal and of public-policy planning.
https://en.wikipedia.org/wiki/Pruitt%E2%80%93Igoe