Reason to breed mass amounts of puppies?

As it stands, is there a reason to breed a ton of puppies just for the heck of it? I've seen some dens FULL and I personally haven't figured out why. Is it trying to get those more uncommon coat colors, genetics, etc? Is there an achievement for chasing a bunch of wolves (which will inevitably happen when the uninteresting puppies are of age)?

This is definitely a more person by person thing I suppose, so I'd appreciate any and all input :>

My den isn't so full at the moment but - I mass breed for stats, because I'm already planning for the next generation lead wolf and such - so me studding my females to high stat males on mass isn't so uncommon

Looks, at the moment, is very secondary to me

My den is bursting at the seams LOL. I bred a ton bcus it was everyone's first heat, and the first and last heats are special to me. I'm not sure if I'll breed the other heats because selling pups is hard! Sometimes I do like to see what my wolves create too. I've had 1/24 deaths because about half of my pack is made of pupsitters so... time to downsize!

I breed as many pups as possible because this is a breeding sim lol, my playing style is focused on getting pretty wolves and then making pretty pups with them. I like to up my chances of getting the best outcome by breeding often and I don't really have a problem chasing or selling the ones I don't like. I guess I'm just positive about it, but I think pups are the best part of the game.

I'm breeding a lot right now because out the gate I snagged whatever NBWs I could to create scouts, hunters, an herbalist, etc. They've been fulfilling those roles while I worked on getting more permanent pack members, so they'll be replaced with pretty pups. After that, I can chill with the breeding!