When you put a puzzle online, people who solve it have to somehow say "I am not stupid. I demonstrate my non stupidity by solving that puzzle".

On that note...I too solved that puzzle! I, too, am not stupid!

Though seriously puzzles like this need to not underestimate the takers. I think many, when met by the syn bit, immediately started going down the process of actually constructing a custom handshake with their server, before perhaps thinking "Nah, not worth the trouble".