Because mainline pilots have given away so many jobs and the only way to get to mainline is to put in the time at a regional.
I agree with you that you should be p'd off, but your anger is completely misdirected. You and I are in the same boat. We both want to fly at mainline, but the jobs just aren't there right now...and it's because of scope. Period.
And to prove this is not a thread drift, THIS is why CAL ALPA should be fighting this flying. Its a violation of scope.