Why should credit at reasonable rates be available for all?Explain in brief?

Credit should be available at reasonable rates to all so that economic condition of every people who takes the loan will improve. If the interest on credit will increase like in informal credit sector, then people taking the loan for some developmental activities, after earning profits ,will have to spend their maximum income on paying back the high interest rate along with principle amount . Sometimes, person is unable to pay back the loan . This will drag him in dept - trap

As a result , credit instead of increasing his financial condition , let him worse off than before.