I was an A&P before I flew a tailwheel, so I had seen a number of damaged planes from groundloops. When I bought my first tailwheel plane (a C-170), I told myself it was not going to happen to me. I've made some pretty ugly landings, but I will not ever let that tail come around!
When I teach in a taildragger, there's lots of (full runway length) high and low speed taxiing, lots of distractions presented, lots of crosswinds, and you need to do real nice wheel landings before I cut you loose.
Also, many people assume it only happens on landing. Well, that's not the case, and when it happens on takeoff, you've just added full power, and all that energy makes the whole thing occur more quickly and often with more damage.