The point being made is that these areas become more expensive after the rail is built, so even if the rail passed though a lower income neighbourhood, it will gentrify in the long term.

> The area around the LRT lines definitely attract investment, but if you look at who actually uses the line a few years in, it’s mostly rich people. Why? Because they’re the only people who can afford to take it – not because the fares are too high, but because real estate in the immediate walking area around stations becomes too expensive.

I don't know if this is actually true, but intuitively it seems plausible.