Given that rigid, long term seniority systems are largely the preserve of 'legacy' carriers then whats the big deal if they are not aroud in 20 years? By definition the seniority systems won't be either. Besides, as I've previously said there are plenty of opportunites around for people to take their skills and experience to other operates as direct entry FOs and Captains. The only people who are inconvenienced are those who think they should be able to move to a large 'legacy' carrier, on similar terms, bypassing the internal candidates that the destination carrier would normally promote.