That is because you only want to have the discussion on your terms, that is: gun control. I have challenged your premise and gave you reasons why I found it invalid. You have not responded to my assertions, and just continued to insist that I cede you this point: that mass shooting are a result of lax gun laws, which should be made stricter. That I don't accept that premise does not make me unserious.
Anyway, we will end our back-and-forth's as you wish, as they are fruitless, as I said earlier. No hard feelings.