Well there's nothing we can really do for this game now, Nintendo is already moving onto Splatoon 2. And to argue your point, if you can make a better matchmaking system that can perfectly balance hundreds of games at the same time with the weapon diversity that Splatoon has, be my guest. Nintendo did the best they could and Splatoon really was an experimental game at the end of the day.
I do agree that there are some very not fun matches due to other people disconnecting or afk-ing, but what you had was just really unlucky so I understand your salt. AI wouldn't solve this problem, in my opinion, but rather they should focus on stronger servers and easier transfer of data between players, which is something that the devs have already hinted towards. Some people just have bad internet (and others are just jerks), but they want to try and play the game and have some fun as well.