What the Heck is with Business Formal in San Diego?

This has been bugging me for a while. My day to day dress is pretty casual, but I have absolutely no qualms with wearing a suit if the situation calls for it. Or wearing khakis and a button down, or anything in between. Yesterday I went to the Experimental Biology Conference at the San Diego Convention Center to help with a Wikipedia event, sponsored by the Simons Foundation and the ASBMB. I'll blog about this event later, but after the conference I was speaking with a fellow from the Simons Foundation about what one wears to science conferences. We really didn't have much of a conclusion. We saw people in dress ranging from suits, to sportcoats, to khakis and polos, all the way to shorts and a tank top. While the first and the last were pretty uncommon, it does show the kind of breadth of what is allowable. That being said, this didn't bother me too much. There wasn't much of a dress code, and people wore what they thought would work.

I've been to a couple events in San Diego that said Business Formal Required. Then you go and it's the casual end of business casual. Khakis, dark jeans, and casual leather shoes. I've felt terribly overdressed, but I'd rather be overdressed than underdressed. I'm not sure what leads to this in San Diego. Perhaps it's just the sense of casualness that pervades the city. Regardless, I'd much prefer honesty. Just say Business Casual if it's what you want. Not this weird Business-formal-but-in-San-Diego-so-actually-business-casual. I do wonder if this is a thing in other places. (I know for a sure it isn't in both DC and NYC)