Please fix your horrendous client

Literally everybody I play with describes the League of Legends client in the same way: disgustingly buggy. I recently had the good fortune of entering a game lobby and bringing up my masteries screen only to find I couldn't close it because a large picture of Gragas was covering the "exit masteries" button. I couldn't pick a champ and got kicked from the lobby and had to wait 6 minutes to enter another game.

I've noticed slight improvement in the chat and friends lists, but seriously, from a large business point of view, having a buggy client is simply ridiculous. If I ran a pub where the front door was covered in jaggy nails and the welcome mat was made of broken glass I would expect to lose customers, so how is it so low on Riot's priorities to have a smoothly functioning client with which you an enter a game without issue? It's so simple, if people enjoy the game without getting frustrated by the client, they buy skins, Riot profits. If they don't, they go and play Dota 2 or any game which lets them play without massive amounts of hassle and pay money to other companies. It's not much to ask.