Seriously, I'm a little old lady who waited in the checkout line yesterday behind a man who, after all his purchases were rung up, dug in his tight back pocket (those skinny jeans, doncha know) until he could bring out his wallet. Then he searched around for the card he wanted to use, swiped it, entered the pin - incorrectly - twice - before finally completing his purchase. If I wrote checks I could have gotten a couple done during the time it took him to finish.
I actually get held up more by things like that than by people writing checks. Six of one, half dozen of another - it's a delay either way. Annoying, but not worth more than a good eyeroll when it happens.