Dirt Hurts.
Accidents don't happen up in the air, except in the extraordinarily rare case of a mid-air collision. Damage happens when airplanes encounter dirt, so it's no surprise that pilots tend to crack up airplanes during takeoff and landing practice. These skills are critical to practice on a regular basis. To fly an airplane is really pretty simple. Cruising from A to B is a no-brainer, and there's very little learning that takes place while in level flight or while making course corrections.
The place where flying skill comes into play is during the takeoff and (especially) landing phase of flight. That's when judgment of angles and speeds, maneuvering ability and multi-tasking all come to the fore. But for every hour of "normal flying", a pilot may only spend a minute or two on the transition from air to ground. That's why good pilots sharpen their skills by going out to the field and doing a dozen laps around the pattern, focusing on those critical moments when the airplane transitions from a ground-based to sky-based vehicle. To further heighten the training effectiveness, we don't just do this practice in perfect conditions. We intentionally land crosswind at times, because sometimes you *have* to land that way and it's good to know how before you need it. We may practice in gusty or turbulent conditions, because again, sometimes you don't have a choice, and there's no pulling over to the curb when you're flying. If you aren't ready for the worst, it's sure to come and bite you when there's no alternative.
Test flights on a new aircraft are designed to find out how the airplane flies, and to uncover any flaws that might not show up in simulations. A simulation is only as good as the numerical model, and we know the models aren't perfect. Flight test refines the model and improves the simulation accuracy. I'd be surprised if there *weren't* problems during the testing phase; it would suggest that the tests aren't rigorous enough.
A tail scrape isn't a major accident, by any means. Based on the past history of these aircraft designers, I'm sure that by the time the program is complete they'll have figured out what tweaks to make and they'll have an aircraft and spacecraft that work properly.
MGF