You seem to be misreading the parent comment. It isn't complaining about small businesses getting loans, it's complaining about them having to pay a higher interest rate than large corporations. (Presumably the reasons for that are a combination of the corporations being "too big to fail" and their loans being collateralized.)

Yeah, you're right. I didn't think any sane person that's eligible for an SBA loan would be complaining about a 4% interest rate. Private unsecured small business loans run like 20%.