Ok call me stupid but without a professional analysis of the FDR, which, to the best of my knowledge, has not happened yet I call BS on this grounding hysteria.
We still don’t have the Lion air full report but to me the principal cause is faulty sensors and gross negligence: this aircraft should never have been used for passengers flights. The MCAS is most probably a contributing factor and reflects poorly on Boeing but I still do not see it in itself as a showstopper. As for the Ethiopian crash we are way too early to draw any conclusion. An immediate airspace ban of the whole fleet is utter madness. A progressive grounding out of extreme caution ? Ok. But what is going on right now is completely out of control (pun intended).