Main reason why people quit.
Lots of people I know play clash or used to. One thing they all had in mutual was the frustration with walls and hero levels and costs. Although all contributed to there exit, walls were the most annoying thing for them. As most of them were town hall 8, I feel town hall8s should have the opportunity to do walls with elixir. I'm a new town hall 9 and I maxed everything out in town hall 8, but not everyone has that patience.
At least 1 day a week a town hall 8 should be able to spend elixir on walls alongside gold to make the process faster and not get bored of the game.