It's an engine for frustration, though. Dragon's Lair is unplayable today because of it's 'arcade tuning', and while people appreciate the art and gameplay it's plainly evident that Don Bluth's lust for quarters ruined the game. Likewise, I don't think any gamers are going to look back on Clash of Clans or Candy Crush and think "that was a well-made, fun game". It's ok to do that, but disrespectful to the player.