I'd be more inclined to accept his opinion if he started with the ADIRUs falsely reporting stalls, the genesis of both crashes. I don't see an alerting system being proposed that reported false reports of other reporting systems. I'd also be backing him if he was for grounding every single existing plane immediately until it was fitted with a state-of-the-art crew alerting system if he believed them to be fundamentally unsafe.
Since neither of these seem of any concern, it just comes across as ax-grinding
I support the decision of the purchasing airlines to specify if they want to fly with the long-time standard configuration or to buy the entirely new one. If American Airlines, for example, decides they need it then it's up to Boeing to decide if it's worth the separate certification costs to provide it. If Southwest's risk analysis shows that the alerting system won't make their operations safer then the existing option should be available to them. Make two new models for each variant: -7AS and -10AS for the alerting system version. If those aren't economical to produce or there are no buyers then Boeing can cancel those variants.