If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.
I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.
The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.
But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.
Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?
IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .
This is where training, and experience become a major player. Prioritization of tasks, and flying the airplane always has to come first. The undue activation of the stick shaker would lead you into the unreliable airspeed checklist. At some point, as the stick forces keep getting heavier towards nose down, but lighten up as you trim nose up, one would believe that the crew would begin to think there was a problem with the stab trim. Since it's not doing what you told it to, and go into that check list.
The airplane will keep flying with unreliable airspeed, and an undue stick shaker, uncommanded stabilizer motion, or a runaway stab is a much bigger threat.
Probably the most famous example of what I'm getting at is United 232. Al Haynes and his crew were handed an airplane that was essentially unflyable, with multiple failures no one ever thought were going to happen. There wasn't a single check list that would have helped them recover the airplane. They fell back on their training and experience (IIRC, there was over 60,000+ hours of combined flight time in that cockpit), and they made the outcome, bad as it was, much better than it could have been.
Just about any modern airplane will exhibit multiple failures with bad air data inputs, the 737 isn't alone in that regard.
I'll again include this snippet from an airplane operating manual.
"Checklists cannot be created for all conceivable situations and are not intended to
replace good judgment. In some situations, at the captain’s discretion, checklist
deviation(s) may be necessary."
It still applies in any airplane.