There is a very simple procedure in place for u/s screens as described - a manual safety demonstration. It isn't optional, it is mandatory for the CC to do so. If a passenger believes that he/she has not received a satisfactory safety briefing, as required, their first stop should be the CAA. It is absolutely appropriate that (as discussed by PAXboy) managers are held to account by customers for their decisions: Such accounting is done by the CAA.
F3G may be correct (despite the dramatic prose) that this is not acceptable - what makes his post tedious is the immaturity of the linkage to another perceived issue, yet again, for no visible reason beyond the usual malice and self-aggrandisemnt.