If I understand it correctly - there is a limited number of these Visas and this mega-project used up most of them.

If true, then this scheme is indeed taking opportunity away from Harlem and other areas it was intended to help.

That's a fair point. But have you considered that maybe Harlem would be hard pressed to find investors, even if the investors got a Visa? It would only take away investment from other areas if a) all the investment visa spots are fully allocated and b) If the investors would have given the money to some low-income community instead.

I'm certainly not an expert on this, but it sounds plausible to me that at least one of the aforementioned conditions is not true.

According to the article there's a 15 year waiting list for these Visas for Chinese investors (it's not clear FTA why it would differ based on country of origin).

It sounds like there's enough demand for this program to work (mostly) as intended.