FWIW, I don't necessarily think that's always the case.
- I'm not straight out of undergrad
- I didn't decide to pursue a career in veterinary medicine until I had already graduated with my bachelor's degree (admittedly, I was already a biology major)
- I was not a particularly high-performing student, academically speaking
- I went back to school for a post-bacc to prove I could handle a heavy workload, perform well academically, and juggle working and having fun
The reason they want you to take biochem and genetics and other upper-division science courses is that that will be the stuff you are learning about 5 days a week in class, 2 days a week at home on your own. They want to know that you aren't going to be drowning and flustered your first day at school, because they dive right in. It's a lot of information to cram into four years, and they want to know that you have the fundamentals covered.
As for the other stuff, I think they mostly want well-rounded individuals. They want people who can survive the sometimes-crushing workload that they have to (apologetically) load onto you, because they don't want to break you.
WSU is pretty diverse, though, as far as vet schools go! Check out the class statistics:
http://dvm.vetmed.wsu.edu/admissions/class-statistics/class-of-2019
I know those are just numbers, but I can tell you that lots of people here have interests in things I've never even had the opportunity to experience, and they come from all over the country.
Anyway, I gotta go back to studying. Good luck, everyone! I am so looking forward to seeing all your bright shining faces come interview time! I'm sending out nothing but GOOD VIBES.