How can you make so little yet be told to pay in $1000??!

I don't get it...when you have kids and you file your taxes if you not in the high middle class or rich high class and your just an average person working your butt off to make sure that the mortgage and bills get paid then you shouldn't have to pay in a $1,000!!! That's just crap. I mean he's paying child support, paying a mortgage and all the bills and goodness knows what else going out and not to mention until last year or so he was paying hundreds a week for child care and now he can't even get EIC...that's just wrong to me. I mean he paid in through out the year and basically because he working a part time second job on the weekends only he's making too much to get EIC now and now he has to pay in...ugh just doesn't seem right but what can you do but just pay it...dang!