[lukan]

"If you don't want something bigger than you to be entirely justified in killing you for no reason, you cannot believe yourself to be entirely justified doing the same."

For the reason of it being a danger. And that my energy is spend more effective on other things, than trying to save life that potentially carries diseases and goes straight to any open wound or eyes. So they come on purpose, not by mistake.

If that is no reason to you, you may continue to catch and save flies if that is your thing, but please don't say "no reason" when you mean "no valid reason to you".