If you are putting candidates into the pool, that means you desire their qualities and qualifications and feel that they are deserving of a job at your company. It's not like you put someone into the pool because you feel sorry for them... "You're not the best, but your not the worst... so SURE let's give you the pool."
Poolies are as good as new hires. There is a standard that you must meet in order to be as good as hired (or also known as placed in the pool). For that reason there should be minimal differences in who is better than another. There shouldn't be a large gap, because it's my belief that a company like AC has extremely high standards for their employees. So anyone making it through enough to be placed in the pool must be better than just good enough.
When you are sorting through people that scored 90.5% or 90.6% on their interview, they really aren't that much different. Especially in the case of AC where everyone starts out as a First Officer on something. Ok... if you were hiring Direct Entry Captain's and F/O's, I can see there being a larger gap between qualified candidates. But at the end of the day, these aren't college applications. Everyone in the pool is deserving of a shot. As much of a shot that they would of had if a pool didn't exist and the demand would deem them a direct spot like the case was many years ago. But just because there's a pool, some smart@ss will say that ones frustration with not being selected MUST be an indication to an entitlement problem. It really is not. It's a matter of timing. Look at Encore, they have a pool now. Anyone who is in the pool today would probably have received a ground school offer instead of a pool offer would they have interviewed a year ago. But now, the poolies wait. So linking frustration to entitlement is in my opinion completely out of context.
So what's fair is picking all your desired candidates in the order you told them they are successful. But since when was aviation fair ?
Patience is definitely a virtue, and slappy, I really feel for you man. You've been in the pool for almost 2 years now and that's a lot of time for a company to be prancing around in order to offer you a spot. My theory is, as soon as a company informs your CP that you are getting picked up by them, it's courtesy to take you sooner rather than later. I don't know, but most CP's won't offer you career advancements at companies if they know you are leaving. And 3 years is a time frame where you possibly have been overlooked for quite a few advancements if I'm not incorrect?
I'm not saying you're entitled to anything, but common courtesy seems to have extended its welcome in your case and that really sucks.