I'm less anti-streetcar than some urban transit nerds. It's not that the general critiques are wrong, but I do think they miss that even a slow in traffic fixed route system has advantages over buses. Those advantages aren't necessarily worth the cost, but I'd rather have a nice trolley than F-35s. We spend lots of money on stupid things, I'll take spending some money on nice things, even if they aren't as nice as they should be.
But the BQX does sound like a project hatched by people who aren't aware that lots of people in New York City actually use the public transit system to get around. Without fare integration and proper subway connections it's just a ridiculous project.
For some reason people who don't ride transit make all of our transit decisions. And they fail to even consider the reasons they don't ride transit when they do so. It needs to be convenient and reasonably frequent. If there's one thing non-transit riders could bring to the table it's an understanding of why they don't ride it.