It absolutly should be rewarded because players cant be bothered to say "thank you for playing well" etc all the time, and an honor system could be a very nice instrument for that (if it was only one click, and if it could lead to a small amount of IP for example), it is not like in real life were your positive aspect on players is easily translated into positive feedback for you via body language or friendship. It is not a bad idea to put some nice and better systems in place that promote a friendly minded enviroment as long as they dont get abused too much.
In casual game modes i give advice to players all the time, tell them about item builds or websites for champion guides or statistics, and often they dont really say anything, but when one of those days after the game that "helpful" thingy shows up it is actually kind of nice, sadly it does not really do anything and its basically just a waste of time to players to honor someone. This "good behavour should be the norm" stuff is just a weird ideology that ignores the reality of social behaviour in a stressful enviroment. There are also other aspects of the philosophy of riots player bahaviour team i disagree with... why not handle negative players in a more understanding way like saying "you have been reported for overly negative impact on chat communication. we know this type of teamgame with strangers can be stressful at times, but you should take some time to cool off. All non casual game modes have been disabled for your account for an hour, and please afterwards make sure yourself that you are ready to play again." Maybe actual bans etc are more effective, but Riot should really not overstep their boundaries as a game too much in terms of education. Negative behaviour should be seen as a symptom and i think there still is alot that can be done about the core problems.