Though diverging OT, but I believe there were strict restrictions about credit unions lending money to business owners. A credit card is technically a "loan" persay, so they may not have the legal flexibility to do much compared to the big banks.
It's only recently that small business owners have started complaining about this to the US government as more big banks are unwilling to lend money to business owners.
Credit Union Small Business Lending Act Would Help Small Businesses Find Capital
The Credit Union Small Business Lending Act (H.R. 4191) is bipartisan legislation introduced by Kurt Schrader (D-Ore.) and Steve Chabot (R-Ohio), that would make it easier for credit unions to participate in the SBA small business loan programs.