In a game of cards each person is dealt a specific collection of cards, called “hand”. Here the hand is being compared to the talents and abilities that you inherit at birth.
Some people use their surroundings as an excuse not to make something out of their lives. They focus the negative without realizing that they too have abilities (whole hand) that they could be utilized to make a better life.
Going back to the previous lines, the “bull” could also be the system, that puts down the people and denies them a well suited job even if they have the adequate skills (the whole hand).
In a clever line using both the literal and figurative meanings of bullshit, Lupe argues that this is straight up bs, coming directly from the source.

Also, bullshit is the name of a card game, where every time someone suspects you of bluffing your cards, they say “bullshit”. Lupe is really going crazy with these card references.