Why are poblanos sometimes called pasillas? Background information: poblano peppers are one of the most common peppers in Mexican food. Pasilla peppers are something entirely different - the dried form of the chilaca.

I'm originally from Texas, where poblanos are commonly found in grocery stores. I moved to California a while back, and here they're still pretty easy to find, but they're always labeled "pasilla". Even at a local produce market with a decent amount of Mexican food (and Spanish-speaking employees) - and just recently I noticed they even have anchos (dried poblanos) labeled as "dried pasillas". I did manage to find one local Mexican restaurant menu online describing a chile relleno as a stuffed poblano, but otherwise it seems pretty universal.

So where did this come from? Via the above-linked wikipedia article, I did find a website saying it's the fault of the California produce industry for labeling them this way, but that's not the original reason. Is it all just the result of a single person getting it wrong a long time ago, and an entire produce industry building off of that?
I have not been able to find any kind of detailed history of the pepper crop in California online.

However, I will observe that I've only seen chilaca peppers available in Northern California in the last 5 years.  Previously, one never saw them, even at Latin markets.  On the other hand, California grows enormous quantities of poblano peppers, which are larger, hardier, and have a longer shelf life than chilacas when fresh.  Based on that, I suspect that some enterprising, dishonest produce supplier started supplying ancho peppers as pasillas to Mexicans in California decades ago, and after several decades of misnaming, the new names stuck.

I'll also observe that the dried poblanos sold as "anchos" in NorCal are a bit hotter than the ones sold as "pasilla", so it's also likely that there's two different varietals, bred here.  So it's also possible that whoever bred the milder poblanos named them "pasillas" to differentiate them from the hotter ones, confusing everyone.