

Sarek felt that he could have demonstrated more affection towards his human wife in a way that was meaningful to her. That is not the same thing as saying that Vulcan culture is unaffectionate, or that other Vulcans would consider Sarek as not affectionate.
I think it would have been cool to have 1 or 2 Kazon episodes, and then maybe a surprise one or two seasons later when Voyager discovers they had been followed or something. But it was just not a good idea to try and make them the main antagonists as long as they did.