Why are the Bennet's connections considered to "inferior"?

In Victorian England, social status was determined by family connections and on a smaller scale, how one earned money. Although Mr. Bennet owned the estate, Longbourn, he was not considered gentry rather than coming from a middle class background. Mr. Bennet married beneath him. He married the daughter of a mere attorney in Meryton. Her brother was a mere businessman. These connections were considered inferior relegating the Bennet's to a lower social status.