GE Software Engineer interview questions

I applied online, Recieved call from hr to have a online test and i have completed that and got call from hr that I have cleared the test, now interview will be scheduled, Interview went very good and answered all the questions, and since only one round was scheduled for that day. I was exepecting call from hr and i call myself after 2 days and than hr told that i am rejected. I was shocked as on what basis they decided when interview went very good. If they have to consider some other factors than why wasting candidate time by taking interview. Pathetic experience