When a woman in a black catsuit saves you from an armed gunman intent on putting a bullet in your head, you say "Thank you." You do not do this.
College Humor calls this skit "Black Widow is not a Fake Nerd Girl." Technically she's not a nerd girl at all, just your average deadly secret agent/assassin turned superhero. You can be in the Avengers without being an Avengers fan. She's just doing her job — a job that allows for a little tranquilizer leeway when it comes to aggressive geeks.