Well, depending on how one’s alliance may be, asking for ANY rares which have hybrids can potentially be a discard. Even a good handful of commons are totally wasted requests. I always donate what I can that isn’t going towards my roster (the amount of Utahraptor I’ve given away is extraordinary, to name but a simple example) but it is certainly disheartening to always see the same requests for things I either have nothing of, PERIOD, or I use pretty much as soon as I can get enough for a single fuse.
I still try to request some pretty hard-to-come-by DNA (Dilophosaurus and such) because even just a smidgling helps wonderfully as I am super-close anyway to certain goal points.
Besides, if I didn’t do that, what else am I really going to ask for in my situation? Tarbosaurus? Need ungodly amounts to do anything whatsoever so requests are mostly pointless considering it’s one of those niche commons people are reluctant to give up. Irritator G2? Sure, guaranteed, but I have nowhere remotely enough coin to level up my Suchotator any further until another pay period (I couldn’t partake in recent sales as Christmas gifts broke me).
It’s a difficult balance of what can best be salvaged out of people’s personal situations.