Being a cat blogger, I read other cat blogs. Being a foster mom, I read other foster blogs. Like you I really enjoy getting to know other people's cats and kittens and my heart breaks when a particular favorite of mine either passes away or is adopted out. But unlike a lot of people, I will never tell a foster family they 'have to keep' a kitten.
I can not keep them all. I can't even keep one a year, and I can't even keep all the ones that get a claw inside my heart.. the ones that really hurt to let go. But really, if it didn't hurt to let them go then I shouldn't be fostering. It is 'part of the job' and I accept that pain is part of it because I know how much good it does. It helps the cats, it helps me, it helps the shelter, it helps the new owners, and in a roundabout way it helps you.. (because... kittens). Keeping more kitties would mean I wouldn't be able to foster.
I also know I am not the only one who fosters or rescues who has fallen in love with a kitty and had people chiming in that the kitty should be kept. I KNOW this is said with the absolute best intentions and with love but - and I say this with love and respect to those of you out there that have done this not knowing - it can be overwhelming. We do love these kittens, we really don't want to give them up, but we know that doing so is in the best interest of the kitty. The thought has crossed our minds, we have wrestled with it, and we respect our own limitations knowing that keeping 'just one more' would upset a delicate balance in our lives it could harm not only the kitty by not giving it the best life possible, but our resident pets who would have to deal with yet another interloper sleeping in the good spots and eating the food and competing for treats, and ourselves because we know we put ourselves in this position emotionally and financially.
When you are tempted to ask someone who rescues why they aren't keeping a particular animal, please first ask yourself why you aren't adopting another pet. Chances are all the same reasons apply and a few others.