I don't know this person's particular case but it's possible that he made significant progress on his idea between submissions.
What I'm really saying is that just because applying is so quick and easy, it should not be taken lightly. In fact I think the application process should be made a lot more difficult to attract a higher concentration.
Am I the only one feeling like this? I hold Pg and his team to a high regard. A No from him is different than any other No. So of course I would want the highest probability of acceptance when I send my pitch.
What it requires is people to take time to think their plans through very carefully and summarise them effectively. If you have this summary in your head at all times then the important part of applying will always be easy; any additional requirements would just be makework.
I also respect PG and YC crew but I don't take a "no" as being so definitive as you do, I guess. There could be many reasons as he states in whynot. Maybe you don't have the right team. Maybe they couldn't see the vision in your answers. Maybe they didn't see the market.
All 3 of those maybes are subject to change imo. In between applications, your team could've changed. The vision might have become more clear with new news from the industry. Perhaps the market is becoming more apparent due to players entering the market.
I think the "one and done" attitude is more likely to be detrimental. Just because you try more than once doesn't mean you're doing it lightly.