Wow, you must be super duper extra serious... I mean all those collectors and target shooters definitely aren't SERIOUS shooters, and their guns aren't SERIOUS either.
What a condescending load of crap.
I think your reading too much into this and over reacting...I don't think it was condescending either.
I think he used serious to mean for self defense/home defense/competition as opposed to for recreation/hobby/collection.