This is significant, because stopping a runaway by opposing it with the yoke leaves the airplane close to being in trim, and toggling the cutout switches becomes a clean-up operation to prevent a recurrence. This, apparently, is as far as pilot simulator training for trim runaway goes. In the case of MCAS, however, toggling the swiches is the only way to stop it, and it leaves the airplane significantly out of trim.
This is what the Ethiopian Airlines flight crew did, but then they found it impossible to put the airplane back in trim because the load on the stabilizer jackscrew was resisting their attempts at manual trimming. This problem is mentioned in the documentation (though not, significantly, in the checkist that the FAA's response to the Lion Air crash directed pilots' attention to), but in that documentation, it rather vaguely says this might be a problem, and if so, it might be necessary to pitch the airplane further in the direction of the mis-trim to reduce the load on the jackscrew so that it can be cranked in manually. It suggests that several cycles may be necessary to complete the action.
If you are, as the Ethiopian Airlines crew were, at low alttude in an airplane mis-trimmed to dive, this is not a viable option, which is why they re-engaged the electric trim in the hope of correcting the problem. The article mentions a video, that was briefly available, of an exercise to test this scenario, in which the professional pilots struggled to maintain control.
It is clear from this that MCAS runaway is sufficiently different from the sort of trim runaways that pilots have previously experienced, either for real or in their simulator training, and this alone should arguably have been sufficient reason for additional training to prepare for MCAS failure. Even after the Lion Air crash, the response of Boeing and the FAA failed to make this distinction clear -- the message was 'this is merely a form of trim runaway, just like what you have trained for', which it is not.
And then there is the separate issue of not using both AofA inputs, apparently just to keep the lie that there was nothing about MCAS that pilots needed to know about.
None of the above is my own opinion - they are issues that professional pilots, engineers and safety experts have forcefully raised. Captain Dan Carey himself initially went along with Boeing's take on the issue, until more information about the issue came out. If you have contrary experience of 737 training and operation, your point of view would be most welcome.
The panel’s majority members were best embodied by subcommittee Chairman Rick Larsen, an ex-lobbyist New Democrat who delivered an opening statement of head-scratching insipidness: “As I have said before, if the public does not feel safe about flying then they won’t fly; if they don’t fly, airlines don’t need to buy airplanes; if they don’t need to buy airplanes, then airplanes don’t need to be built; and if there is no need to build airplanes, then there will be no jobs in aviation.”
Followed by Congressman Paul Mitchell's lambasting of Captain Dan Carey, the outgoing president of the Allied Pilots Association, for having the temerity to go public with his concerns: "What’s the value [of releasing a secret recording] to the system or the families?... Explain to me what warranted that, sir!" Clearly, the problem here is that the travelling public, and victims' families, have come to learn about MCAS and its role in recent crashes.
When you are trying to spin a story, however, it can be difficult to keep it straight. Here's Sam Graves, ranking Republican on the House Transportation and Infrastructure Committee:
“It’s not the plane I’m concerned about; I think the plane is very safe. We need to concentrate on the pilot ... being trained [for] the aircraft, and being able to fly a plane and not just fly the computer.”
His blame-the-pilots rhetoric does not look so good for Boeing now that we are learning the lengths it went to in order to avoid there being any additional training for pilots.