It is barbaric because animal also have feelings and show emotions. How would they be feeling when they see the blood of their own clans and see being slaughtered. There're tons of other things why it is barbaric, and it has not been disussed in other threads too. I can try to dig out if you're really interested. Besides that, there could be all kinds of psychological consequences because of these barbaric traditions of animal sacrifice. What kind of attitude and personality would be developed on child's mind when they see animals being sacrificed that way.

I listened in BBC yesterday that people in Chitwan celebrated "lakhe dance" (masked dance) perhaps for the first time, why did they need to do that even if it wasn't really the traditions there. Gaijatra is not only limited to Kathmandu. People in Pokhara also celebrates gaijatra too, and perhaps in other towns too.