I alway wondered why so many people (not saying you're one of them) get mad at being charged for misclicks and bots.

It all averages out.

You bid $3 a click because your conversion ratio is x, and paying $3 is worth it. Even if 90% of the traffic is bots, it works out. If Google filtered out all the bots, the conversion ratio for you and your competitors would go up, and your competitors would be willing to pay $27 per click and you'd outbid at $30, being at the exact same result at the end of the month spent for the exact same results.