This interpretation can be supported internally by a close look at the Big Daddy character, on the surface an unlikable domineering “head of household”, but not an aware, discerning, or wise patriarch; the problem  lies in finding dialogue that supports the “need for blessing” from him, either by Brick or Gooper, unless those “blessings are disguised as his inheritance.  That Brick has not provided a worthy heir (the “no-neck monsters” are seen by Big Daddy as inadequate but serve to solidify Gooper’s claim to the family wealth ) is a driving force in the plot, but is a weak argument for claiming the play is “about” approval.  Comparing Big Daddy to Amanda Wingfield in Glass Menagerie, we see that Williams’ real use of domineering heads of household is to underline how they stultify growth from generation to generation.  Big Daddy is an impediment to Brick and Maggie’s reconciling their problems, rather than the focus of their attention.  The sickness that everyone is keeping from Big Daddy is also a symbol of the sickness debilitating the family, the close-mindedness, the untruths and deceptions, and to that degree his death is more desired than his approval.  The play is still “about” Brick’s grief at the loss of his friend, and whether the incompatibility of Brick and Maggie will resolve itself or not.