Trigger, not all CP branches are the same, they dont have rules from HQ, each branch can do things their own way, so I would suggest speaking to your local branch and making sure you are happy with their ways before questioning your donations. Also, if you donate to just CP it will go to HQ rather than your local branch, so you might want to check out where your donation is going.
I dont know of many rescues who turn people away for working part time, but sometimes rescues dont give the real reason for turning people away, for whatever reason. I also think that people who have been turned away should go to at least one more rescue rather than going straight to free ads - we often homed to people who had been turned away from the strictest rescue, as we didn't agree with not homing with young children.
Just to prove not all rescues are like this, I did a home check on Fri for two kittens - they have their nephew living with them who must have been 5 at the oldest (but looked younger), and everyone in the house works (although they all do shift work, so there is generally no more than a few hours between one person leaving and one coming), they will be going on Mon.