I don't think that's true for any of the issues, or airline accidents in general. Remember ultimately we're still talking about very rare events that almost always involve a number of different factors lining up in just the right way.
Even the MAX crashes were 2 out of how many thousands of MCAS equipped flights with no issues and those crashes also required other things to go wrong. It's easy to say MCAS was the obvious cause in retrospect, but it's much less clear it should have been easy to predict that outcome before any investigations were done regardless of how much inside knowledge one had.
This is not at all to excuse the causes, but there is a reason crash investigations take time. Demanding immediate explanations is just asking for wrong conclusions to be reached in the name of expediency. In fact taking the time to fully investigate probably produces better accountability in the long run because it can uncover more subtle but serious problems.