> Well, that should be easy to answer: Simon and Speck are "lightweight" ciphers intended for embedded designs.
You are providing rationale which the NSA is, according to Ashur, unable to provide in the design documentation/rationale. So I think you are missing the point he's trying to make: If you can't tell me why and are doing hand waving you are either incompetent or deliberately dismissive in which case you should not be trusted.
I think that part of the issue is that people (probably including the WG2) hear NSA and then ignore the lightweight part.
To some extent the lightweightness implies lower standard for the security margins. This is in this case compounded by the fact that WG2 had thrown out most of the truly useful NSA recommended Speck/Simon parameter combinations (things like 32b blocks) even before the current turmoil on the basis that they obviously provide insufficient level of security, which is obviously true for general purpose block cipher, but not for lightweight ("IoT-ish" ;)) applications.
On the other hand I somewhat wonder what motivation exactly NSA had for trying to push these algorithms through ISO.
You are providing rationale which the NSA is, according to Ashur, unable to provide in the design documentation/rationale. So I think you are missing the point he's trying to make: If you can't tell me why and are doing hand waving you are either incompetent or deliberately dismissive in which case you should not be trusted.