Triples are necessary for certain things. If you're racing you probably won't have a triple. But if you're touring, or you're towing, or you live in a place with a very varied terrain, you'll enjoy having a triple. If you had a bike that you towed something uphill with, but also road alone, you couldn't have gears wide enough to accommodate both with a double. You can only drop so far from one chainring to another before bad things happen.

This seems counter intuitive, but I actually like the triple I have on my commuter much more than the double I have on my road bike. With the triple I switch between chainrings much more often and freely, with the compact double it requires a thought and effort because I have to triple shift the back and then downshift the front to end up roughly in the same gear. It's a bit jarring. Not saying that I'm not used to it, but chainring shifts are much more smooth on a triple.