Peter Todd is in a very difficult situation. It is difficult to refute absolutely senseless and unsubstantiated accusations.

If Peter Todd starts making excuses now or organizes a big lawsuit, he may not convey the truth to most people. Ordinary people are not inclined to analyze the facts of the case, they will simply remember that Peter Todd is considered Satoshi Nakamoto by some people (respected and authoritative journalists). Therefore, people will assume that Peter Todd is Satoshi Nakamoto.

Peter Todd probably idolized the real Satoshi Nakamoto (the creator of the legendary Bitcoin) and tried to earn his approval. That is why Peter made this strange post on the forum. Satoshi Nakamoto might not have liked the excessive enthusiasm of young Peter Todd, since Satoshi was probably an introvert and valued his anonymity and privacy above all else. Satoshi did not want unnecessary attention to himself. That is why he did not respond to Peter Todd's post. 

Or maybe it was something else - maybe Satoshi was very busy at the time, or maybe he just thought the question had already been answered in detail and there was no point in discussing it further.