All that is true and I get it (really, I do)... but I guess my point and the thread came about trying to understand what it means to be open to idea-stage because surely by definition an idea-stage venture is that- only an idea?
What it means in practice is that they'll receive probably tens of thousands of applications but only be able to accept 20 (https://news.ycombinator.com/item?id=9917491), so your competition will be fierce.
(BTW, see also this note from sama: "We will be slightly more open to solo founders because we think at this stage you still have a good chance of finding a cofounder. But the bar will still remain higher for solo founders given all of our historical data.: -- https://news.ycombinator.com/item?id=9917470)