I personally never got the purpose of having mates.
Sure, people might enjoy roleplaying mostly with one person, but you can easily do that without declaring a mate. I've never made and consistently roleplayed an ordinary character like a wolf, lion, or the ever-annoying warrior cat/normal cat, which might explain my reluctancy, but seriously.
I never understood it, since unless you have a third and also very close friend, or up to six to them, you can't reliably birth pups/kits/cubs/whatever the heck. You'll mostly always need to go to an AC for that, and people say roleplaying birthing is disgusting as well.
In conclusion, I just... Don't get mates. It makes little sense in my opinion, because really, you don't NEED a mate and a lot of people get a mate for every character.
~Neo