The argument for Hudson Yards (I don't actually agree) is that while Times Square is certainly a very busy station, most of the movement that happens there is transferring. And Times Square has nearby stations that other people also use for exiting and entering; Hudson Yards is a long hike from the next closest subway station, and 34th St is not a particularly great walk, with all the Lincoln tunnel traffic and whatnot.

Hudson Yards is also the only station next to the Javits Center, so it has the massive traffic from large convention events like the Auto Show and NYCC.