I actually liked the fishing part. It reminded me a bit of Summer Wars with the whole festival air to it. This was a side story done right, and it even pulled in game functions as a part of the micro-plot.

Lakes have different skill requirements, and for a game, the largest lake unsurprisingly has the highest.

Kirito wasn't aware of something about the game, that's huge. He didn't know that you could Switch on secondary skills. It makes sense because most of his secondary skills we know about (Listening, other detection abilities, stealth?, etc.) were totally focused on combat until just recently. Skills that can only ever benefit oneself.

It fits because he is so anti-social and "I'm going to survive!" that he never for a moment thought he might enjoy himself in the game, the whole reason he should have been playing for in the first place. Being in the beta, he would have had a chance to try it out, but never did. This leads us to believe he was only in it for the grind. Perhaps he finally learned something this episode, instead of just throwing out soundbites that were meant to somehow imply he grew as a person.