For Kevin, due to the "trollish" behavior of Maciej during this competition, Kevin was (validly) very suspicious of Maciej's intention for participating in the program. Of course previous history of Maciej rallying against all YC stands for did not help assuage the fears :)
For Maciej, the rules are the rules. he (fairly) believes you do not have to like someone to keep your end of an agreement.
Here's my position. As this is an EXPERIMENT, YC should have taken the risk. Worst case, they would have had to kick him out of the program. But everyone will see they have been fair. Seen to be fair is a quite important.
I have "clashed" with Maciej before [1] however, i see him as some one who only has a hard bark and will be quite cook in person or once you know him. Dont't be too worried Kevin.
Of course, your house your rules. But still..
I hope YC can rescind and take Pinboard in (I know... I know..:).
[1] http://oonwoye.com/2011/03/09/maciej-of-pinboard-in-nigerian...