<<Big difference is liability. With a personal card it's you. With a business card it's the business - which - ultimately might be you but in many cases it's a corporation.>>

I think not. The application Terms & Conditions explicitly establish personal and company liability:

"By submitting this application, I as the Authorizing Officer designated herein and the Company (a) request that you open an account in the name of the Company, (b) request that Card(s) be issued on that account as indicated on this application and other applications, (c) understand that you will renew and replace the Card(s) until I cancel, (d) agree to be liable for all charges to the Card account made by all Cards issued on the account now or in the future..."