"Netpicking" is extremely common in internet message board style exchanges where words and images can be misinterpreted (intentionally or unintentionally), and dissected for technical or semantic inaccuracies, flaws, loopholes, or exploitable phraseologies.
While the "netpick" may be well-intentioned and innocent at times, it's more often used as a defense mechanism in flame wars and debates. The purpose is to ignore the greater, more obvious point, and instead redirect the discussion to something that probably shouldn't even be up for debate.
Other forms of the "netpick" manifest as pointles and often cruel hypercriticism based on "online-only" standards of excellence, beauty, competence, etc. held by the netpicker, who is most likely nowhere near a position to be judging anyone else by said standards.
"Fail" vs "Win" mentality is often a symptom of "netpickers", who rely on the buffer of anonymous internet identities to protect them from the constant hyper-scrutiny they heap upon others, merely for the purpose of entertainment through pointlessly negative commentary.
"I don't care if she has sharp knees. She's hot, and YOUR last date had to be crated at the end of the night. Stop netpicking."