The problem, from a job seeker's perspective is competition. For the better part of a decade RJ Captains have say waiting for the stagnant environment to lift so they can move on. They have 10,000+ hours in an RJ and will have identical resumes, blue suits, and red ties. (ie all are well qualified)
Meanwhile traditional mainline jobs have been outsourced to larger and larger Rjs over the same time period. For example, the 80-120 seat "mainline" metal that used to be entry level mainline equipment has been outsourced: Bac 1-11, DC9, F28, F100, BAE146... Etc
Finally, consolidation has resulted in WAY fewer mainline companies to apply with.
More competition for fewer jobs = continues stagnation even during a period of growth.