It isn't. Or at least the max isn't. It's a big change from the original 737, a change that makes the type IMHO unairworthy beyond repair.
But that is not even the biggest issue, its the fact that boeing thinks they should withold essential information (such as the existence of an MCAS) from the pilots, who ultimaltely bear the responsibility of the safety of hundreds of passagers. Even now, in the light of what happened, apparently boeing still hasn't changed policy.