If an airplane crashes because it's hit by a missile, or because there's a bomb aboard, or because a suicidal pilot flies it into a mountain, that is no reason to ground it.
Thus, more evidence is required to ground an airplane (that has, after all, gone through the certification process), than two crashes.
I agree with the assessment that the MAX has a problem; I'm saying "oh, two crashes" by itself is not sufficient evidence for that conclusion.
As someone pointed out in this thread, there were three B767 hull losses between September and November 2001, but two of those were caused by 9/11 terrorists and don't tell you much about the airworthiness of the aircraft.
FWIW, IMHO it's not pedantry, it's precisely the core of the discussion. The 737 MAX was deemed airworthy during certification, and deemed airworthy after Lion Air, and a further crash by itself does not change that. It is only the details and circumstances of the second crash that can provide evidence to challenge the conclusion of airworthiness. Just reflexively saying "crash, ground it all" is mistaken.
On 24 March 2015, Germanwings Flight 9525, using an Airbus A320, flying from Barcelona to Düsseldorf crashed near Digne in the Southern French Alps, killing all 150 on board. They didn't know it was a suicide pilot until after they investigated. Yet, A320s kept flying in the meantime.
On 29 March 2015, Air Canada Flight 624, using an Airbus A320, flying from Toronto to Halifax carrying 138 people crash landed short of the runway. The aircraft was badly damaged and 23 people were injured.
On 14 April 2015, Asiana Airlines Flight 162, an Airbus A320 with 82 people on board, lost height on final approach to Hiroshima Airport in Mihara, Japan, struck an antenna, and skidded onto the runway on its tail, spinning 180 degrees before coming to a stop. Its main landing gear collapsed and the aircraft suffered damage to its left wing and left engine. 27 of the 82 people on board were injured.
Three incidents, on respectable, high-safety airlines within 3 weeks of each other all with the Airbus A320. Yet, those planes weren't grounded, not even for five minutes. Three serious incidents within 3 weeks of each other is "empirical evidence" that the A320 is unsafe.
But we have a crash from Ethiopian Air, on a plane where the first officer had only 200 hours of total flight experience. And another crash months ago on Lion Air (a ridiculously unsafe airline) and that's "empirical evidence" that the airplane is bad?
Lion Air should be grounded. Ethiopia shouldn't be flying planes with student pilots in the right seat. There may be issues with the 8 Max, however, it's a fact that inexperienced pilots, bad maintenance, inferior safety processes and negligence will exacerbate any potential flaws in the aircraft. The fact is that in the case of Lion Air, if it were Southwest Airlines operating those flights in Indonesia, flight 610 never would have crashed. Lion Air had days of reported issues before the crash and they ignored them. Look at Lion Air's incidents and accidents: https://en.wikipedia.org/wiki/Lion_Air#Incidents_and_acciden... It seems that can't even taxi a 737 safety, let alone be trusted to fly one. And right now we're complaining about the FAA? We should be complaining about airlines that are being allowed to operate with this slipshod respect for safety.
The US, Canada and Europe hasn't had any 8 Max incidents -- the incidents happened in organizations that were operating in ways that would never be allowed in US, Canada, or Europe. That fact seems to be getting ignored in favor of complaining about the FAA or Boeing. The US flies a lot more 8 Maxes than Ethiopia or Lion Air, yet not a single crash. Is that just coincidence or does the US/Canada/Europe just do a better job?
Asiana Airlines Flight 162 was an Airbus A320-232, manufactured in 2007
Air Canada Flight 624 was an Airbus A320-211 manufactured in 1991
Germanwings Flight 9525 was an Airbus A320-211 manufactured in 1990.
The Asiana and Air Canada incidents were similar, but the aircraft were of different models, one was 7 year old and the other was 24 year old. The German Wings and the Air Canada aircraft were similar models, but both planes were 23-24 year old, and the incidents were completely different.
Compare that to the 737 MAX 8. Two fatal crashes, during the same stage of flight, with identical models, of similar age. 2 out of 350 planes crashed, where the fleet is barely one year old on average.
Thus, more evidence is required to ground an airplane (that has, after all, gone through the certification process), than two crashes.