Speaking as an ex Line Training Captain at Arik Air I am in general agreement with the original poster. Whilst the Captain may be proficient in everything technical perhaps he or she may need some education in other areas.
Comments on the PA that apparently have been made will perhaps make a good number of passengers feel insecure. In my experience Nigerian pax in particular tend to nervous of flying.
I would regard the PA's by the Captain to be somewhat immature.
Been gone 3 years now.
Kind regards
Exeng