You are absolutely right. Two points, though: (i) As you see from my comments, my judgments were based on the site, the Nigerian thing is an afterthought and (ii) unfortunately, people do have Bayesian prior probabilities, commonly referred to as prejudices. You cannot avoid them and they need to be addressed sometime. What I said was that if I were from Nigeria, I would be work more on my site to erase any spammish connotations. This is probably true of your boss, too.