This is so true. Lfs had an aquarium labeled Laced Catfish and I bought a Synodontis Angelicus for $6.99. It was shipped in together with the Lace Catfish and the lfs employee didn't know what the Synodontis Angelicus was.
Thing is, your typical employee of a LFS don't know a great deal anyway, I think most of us have experiences with stores where their staff don't have a clue. So expecting them to get their heads round the scientific names of the fish they are selling is a non starter.
I'll be honest with you though, sometimes i'll be reading a thread on here and a sexy scientific sounding name of a fish will come up and i'm thinking, what the hell is that! And i'll have to google it to see what it is.
But I understand what duanes is saying. There is only one scientific name per fish, yet there can be several common names for the same fish depending where you're from, which can muddy the waters somewhat. A good example would be the dennison barb (sahyadria denisonii). It has half a dozen or so different common names.
I'll be honest with you here, again. I had to look that up!!!