Not sure I understand the diagram. It seems to be an L shaped beam, assumed rigid at the bend. The distributed load is of uniform density q0 on the vertical section, but what about the horizontal section? The text suggests that is also uniform, but the diagram implies it declines linearly(?) from a max of q0 to zero at the tip.
By "confounded" loads, do you mean the combination of distributed and point loads on the same beam section, or is it the mix of vertical and horizontal loads that bothers you?