For whatever reason (timing, hiring environment etc.), the message you should probably take away is to strengthen your application. Easiest way is to go to job fairs. After that get some 121 flying on your application, preferably at one of UALs competitors or their regional partners. 135/91/DoD contractor experience won't hurt if it's all you can get in this current hiring environment but 121 time at a non UAX carrier is most ideal.

I know people who had their application in at UAL for six years and others in for six weeks before they got a call during the same calandar year. The hiring environment has changed rapidly several times over the last 5 years. It will probably change again some more. Keep a positive attitude and keep working towards ending up at a career destination for yourself.