Earlier quoted context omitted.
For a homogenous culture of a large corporation, where each dev is a cog in the system, yes, i would agree that this person will not fit. If i had a start-up, i would definitely give this person a good old try, because i can tell that he/she is capable enough to churn out rather advanced projects with complexity higher than just CRUD. Programmers of this type is what i'd call 10x, and one should never dismiss a 10x!
I would be even more hesitant to hire for a startup! can this person grow with the startup? what happens when we have 10, 20, 30+ engineers - how will they work with the team - will they second guess everything? will everything be an argument? I'm not doubting this persons ability - I'm only responding my opinion of this person based solely on this email.
I have never been in a startup that fears arguments. Every startup I have been a part of has lively debates and arguments almost every other day. It's only the large slow moving corporate giants where I see such lack of debate and arguments on what is obviously wrong.
I would go to the extent of saying that a startup that does not encourage arguments in a harmonious fashion would die very soon anyway. Debates and arguments help in weeding out stupid ideas and focus on what that really matters.
This person's email shows that he can have a qualitative argument in a coherent, polite, and non-confrontational fashion - exactly the kind of people you need in startups!