2 events, one every 90,000 flights, versus millions of flights and 1 every 5,000,000. You are correct, regression to the mean cannot be ignored. But superficially it's pretty damning.
A long time ago I coined the saying, randomness comes in lumps. These figures have to be compared, but with a comparison test of one, are fairly meaningless.
Both the EASA and the FAA don't seem to think it is a coincidence, and we can hope at least one of those bodies is independent and competent. They grounded the plane, not the pilots.
So why? 'It's not a coincidence'. Erm, the facts say differently.
I think we all agree that the failure of AoA
information was the prime cause. That loss, or corruption, of data was for two entirely different reasons. To me, that's an horrific coincidence in such a short timescale.
The
prime cause has revealed other issues with the type in general, not just the MAX, several of them pretty serious. Frankly, I think Boeing have a far greater challenge than most people realise when we add the alarming company culture problems to the list of software and mechanical issues. Getting the aircraft back in the air is a multifaceted problem-solving battle. It's akin to being at war on several fronts.