The cap is put in place to prevent the flooding of applications that caused the backlog in the under the old pgpg rules without any caps. The applications get added and added to the queue until we are back to the same problem of parents/grandparents waiting for years and years and years to get their PR.
If you were to submit your parents PR papers under the old rules, your parents would be waiting for probably up to 10-15 years due to backlog. Now your parents won't have to wait that long. So which is it you want. Your parents to wait for over 10 years or more or a heck of a lot sooner under the new system.
The reason you guys are complaining about the 5000 cap is that you guys sort of "first group of queue" that reopens. So your parents will get their PR at a reasonable time. What happens to a new PR that just came to Canada. This PR has to wait 4 years to apply and then submit papers. This new PR's parents will have to wait years and years and years due to all the flood of applications that was submitted before he/she arrived. It is rather unfair that your parents gets to Canada after a decent wait but the new PR's parents have to suffer the wait much longer.
The 5000 cap gives the new PR an equal chance and on equal footing to parents getting PR at a reasonable decent time as the parents who gotten their PR under the new system. So it doesn't matter how long the new system is in place, Everyone's parents will be able to wait at a reasonable time to get their PR. Without the cap, the longer the system was in place, the longer the wait parents have to endure.
For me, I fight for fairness to everyone, Canadians and PRs. If you don't want fairness in the system, that's fine. I'm not going to put any scorn on you but be prepared to be scorned by others who followed the rules faithfully and get denied a spot because you didn't want to be fair and take a spot in the cap away from those that followed the system fairly.