Yellow jackets don't have the tiny hairs covering their bodies that bees do because they are actually a form of wasp, so the are only very minor pollinators.
I'm allergic to their stings, so I have no moral dilima about killing whole nests.
What Rooster Red says is spot on, though, it's a very common misconception that yellow jackets are bees- not only are they wasps, but carnivorous, wasps to boot... Next time you are at a summer wedding, and there's a swirl of black and yellow over the ham, and the salmon? Those jerk party crashers are... yup... yellow jackets. Rude!

What's more, wasps of all varieties have smooth stingers, which means they can sting over and over. (We all know what happens to poor Mrs. Bee after just one sting.)
Gimme a bee anyday, I say! (Though I am really nervous for my friends with bee or wasp allergies. Scary stuff!)
Here in the PNW we have a ground wasp that's SUPER aggressive- my dog and I were out for a walk a couple summers ago, and all of a sudden, tiny wasps were everywhere. We took off running, but she must have gotten stung 5 or 6 times, anyway. They followed us for BLOCKS. It was awful
Like I said... Wasps are jerks.