The preference for tailwheel might be due to it being one of the few clubs in Austria where you can do a tailwheel endorsement so far, and they might want to keep it that way.
BTW, having taken some tailwheel and aeros lessons for fun in the Citabria, I can understand the TW preference. It might be a docile TW aircraft, but still it's a lot more fun and "old school" feeling than in a 152, Katana or Aquila. Granted, it has only limited aerobatic capabilities, but it does indeed appear that there are few other airplanes which bridge the gap between versatility/affordability/durability/fun to fly equally well, other than a Decathlon with a bit more aero capabilities for a slightly higher price. But maybe the Cap 10 is worth a closer look. Thx again, messieurs.