My biased opinion is that the current system good. When I was on probation and commuting, it would have been 100X more stressful not knowing if I would be bumped at the last minute and get a commuter miss. If you are senior and still commuting, it's by choice, (vs temporary situation until you can hold a different base), you probably aren't worried about a commuter miss, and the cost of a revenue ticket or hotel is less significant to you. Also, I think the FAs and gate agents would be the real winners if we switched over to a seniority system, unless we negotiated a carve out but then we would end up with shoe polish on our seatbelts and curly hair in our coffee.