So, the verdict:
"Not enough satisfactory accounts"
"High usage of revolving credit" (no surprise there, that's what this card was gonna be for!)
Whatever. This has seriously made me reconsider whether I need a biz credit card at all. Not that I want to dip into my cash reserves to fund my business, but at least in the short term I may have to until credit card "companies" find their way out of their fear-addled death spirals.
And this was a credit union-backed business card. The CU is Tech CU, and the servicer is FIA Card Services, fka MBNA, owned by Bank of America, one of the primary welfare TARP queens.
What's funny is that I got not one, but two mailers from them this week telling me I was preapproved for a credit card (albeit personal) through FIA Card Services. I understand there are different rules for business vs. personal, but all around it's still pretty nonsensical.