Why did your company expect Google to readily accept peering?

If there was such a large difference in volume they would be choosing to intentionally make it more difficult for themselves.

Google publishes a peering policy. It's reasonable to expect that they will peer with you if you hit all the requirements in the policy.

Afaik, their requirements have never been judgement based: just bandwidth minimums, port types and locations. I would expect that they prioritize new connections in some way, so if you barely hit the criteria and are somewhere well served by transit, you'll be low priority, and the requirements might change before your connection gets setup and if so, you might not get connected because you don't meet the new requirements, but otherwise, seems like if you meet the requirements, send in the application, and have some patience, the peering connection should turn up eventually.

It's not like they have a mostly balanced flows requirement like Tier 1 ISPs usually do. Also, even in their current peering policy, they don't require presence in multiple metros; just substantial traffic (10gbps), fast ports (100G), two pops in the same metro.