Let's face it, we all have our favorite (and least favorite) stores, it's only natural to assume that store employees have their favorite (and least favorite) customers. While I believe that any customer deserves good advice and good service, it's only natural for people to act like people. I deal with my boss' customers every day. There are some I don't like at all, and I'm sure that shows in my body language. Other guys deal with these same people, and like them. There are customers they don't like but I do. I'm positive that the same thing caries over here.
There are just places where you fit. My favorite LFS (Fishy, Inc) is not even close to local for me, it's about 30 miles away. I go there more than anywhere else, because that's where I "fit"
Back to Aqua Hut, I'm going to make it a point to get there soon. I've heard too much about the store to not check it out.
Just guessing about your "leaning toward fish" observation, maybe his invert system is not fully cycled yet?