It helps the company cover their operation more efficiently.
That means a loss of relative seniority for me. By covering their operation more efficiently, they need a few less lineholders - thus a few pilots are pushed down to reserve. Also, they need fewer reserves, so a few more captains are pushed down into the right seat.
Why would pilots want something that reduces demand for pilots?
"I happen to be a proponent of a single payer universal health care plan" -- Barack Obama, June 30, 2003
"I have not said that I am a single payer supporter" -- Barack Obama, August 11, 2009
I agree with you when you say that if someone refuses to learn how to use a bidding system and sets their preferences wrong that's their problem. However, there is a difference between that and trading.
However PBS makes us much more efficient as a whole group especially when it comes to the transition period and training. Vacation is no big deal because vacation trips get dropped and assigned/picked up on a one for one basis. Transition and training trips usually get broken up in the middle creating at least two duty periods on the day it was broken and that happens hundreds of times a month. This is the fundamental reason any company wants PBS. Extra duty periods require pilots to be staffed/hired/upgraded. PBS gets the same block hours covered with less pilots.
Sure with attrition we probably won't furlough and probably won't stop hiring or upgrading but all things equal we will not hire or upgrade on the same scale with PBS.
Maybe PBS would make us more cost competitive so we might be able to steal some more mainline flying or even replace our ALPA brothers at eagle while they go to the street. Im salivating at just the thought of doing that. In that senario we would obviously hire an upgrade much faster than if we had line bidding and didn't get to steal that flying. We may steal it anyway even with line bidding though. Fact is that PBS makes us more efficient which means less pilots for a fixed amount of block hours.