If I'm reading
@Sabertooth post correctly, his Google search provided an answer to his question. He posted it. He didn't personally make a statement of fact regarding shareholders getting PPP funds, the NBER analysis did. Not fully understanding how a fact could be does not preclude one from being upset about said fact.
My impression from that "Key Takeaways" paragraph that he posted is that
businesses who received PPP funds turned around and distributed those funds at their own discretion. Thus shareholders getting a piece of the pie.
I can understand creditors and suppliers getting a piece of the PPP pie because a business doesn't remain open if they can't pay their bills and workers have nothing to do if there are no supplies. The problem I have is owners and shareholders getting funds that were meant for workers. Seems reasonable to me to be upset by this. If this program worked as intended the breakdown of fund distribution would have been more in the neighborhood of 40% to creditors/suppliers to keep businesses open, 60% to workers to keep them employed.
Seems to me that businesses distributing funds to owners/shareholders instead of workers likely contributed to workers becoming unemployed as less money was available for them. Couple that with the additional funds the federal government shoveled to States unemployment coffers which raised monthly benefits also contributed to the reasons why many workers weren't in a hurry to go back to work. They got crapped on, again, by their employers who instead chose to enrich themselves instead of taking care of their workers and, the additional unemployment benefits made the decision rather easy to not return to employment situations where the likelihood of getting crapped on again still remained.