I'll try to respond to all points in this reply.
1. I asked the OP to apply - I assume he is really good.
2. I use the brilliant as a shorthand to say we need people that are very talented.
3. We need very talented people because the code we have, while it looks simple, is very challenging. I was on the Win95 core team at Microsoft - our code is more challenging.
4. We don't do brain teasers in our interviews, they are not an indicator of how effective you'll be (read Word Rules). We mostly have you walk us through your code. And we'll ask you to walk us through how you would approach certain problems.
5. Any workplace is not for everyone. We try to be upfront with applicants as to what they'll be doing here and what the culture is like here. This includes a final "interview" where I go through what they'll be facing here and answer any question of theirs I legally/ethically can. So they come in knowing what to expect.
And hey, if we're not the right place for you that just means you're looking for something different. Never let a job interview define you. And never let a series of no's get you down.