Alright so I get what Aangs son is saying and all and I understand that pro-bending could look like a joke on bending but given this is the 'modern age' and things have changed what is so wrong about pro-bending? I mean, given that Aang and Zuko (and friends) helped create a world where there didn't have to be bending for wars etc anymore (though, of course, they were not going to stop wars breaking out etc still but they did want to keep conflict to a minimum) then besides work shouldn't there be some fun with bending also?
Take Tenzins father, Aang was the one who was ALWAYS off using his bending abilities to play jokes on others etc, if anything, I think Aang would of probably liked the way Pro-Bending is played, maybe not fully but still, I could easily see him watching a game or two, this is what Aang liked, he believed in having fun, Bumi still did when he was older and Aang sorta liked that about his old friend and carried on with it. I guess I see Katara in Tenzin, he takes after his mothers serious side and always wants to get on with work, keeping things like they were etc but Katara understands times have changed so why is Tenzin calling pro-bending bad when his father would of liked the game? Bending is now about having fun, sure we see these turf wars and Amon's group and what not but still, take them out, the worlds changed, fun can be had now, fun that Aang and Zuko help allow after the 100 year war, surely Tenzin just needs to lighten up and remember what his father was like.