Riot's reason for not implementing a Sandbox mode

I just read their reasoning and it seems embarassingly stupid.

It boils down to "we don't want players to expect other players to have skills that would best be developed in a sandbox mode" Except those expectations ALREADY EXIST.

Players expect players to know which walls they can dash and flash over Players expect players to know where to put wards so they illuminate a bush Players expect players to know which items, masteries, and runes to use in order to maximize their damage and survivability in a given situation Players expect players to know the shapes of the hitboxes of their champion and all their champion's abilities And most of all, players expect players to last hit properly in all situations including under turret

Every single one of those skills is better learned in a sandbox mode where you can set up the situations. Players get mad because other players haven't learned these skills and the only way they can learn the skills is to go into games where they encounter players who get mad at them for not knowing these skills. And in a game they might run into learning opportunities for these skills only a handful of times, and then have to sit through 20 minutes of gameplay completely unrelated to these skills while they forget that brief 30 seconds of learning. They want to learn these skills but have no opportunity to.

Even bot games have some toxicity over lane picks because people go in there to practice cs'ing and people fight over having a solo lane to properly practice in. If you don't want the game to have skills that would benefit from practicing in a training mode then you should start making a different game because this one has ward hopping and minion cs'ing and wall flashing so it's been game over on that design goal for YEARS.

If Riot wasn't planning on adding sandbox mode because of technical issues like what has delayed replays or because they thought custom games already had enough features then I could understand, but thinking that training mode would be bad for the game actually makes me angry.

I hope some clever hacker finds a way to make a debug mode in this game to force Riot to make the right choice just like how curse voice forced them to implement buff timers.