Mexican restaurants and bland food.
I'm pretty sure the restaurants are being careful. "Spicy" is highly subjective, so what's tame to one person sets the next person on fire. That's hard for the cook to get right, so they play it safe.
I'm pretty far up there on the scale of spicy food. In my younger days I was forever making dinner that others couldn't eat. Now when I cook now I make it pretty bland so others can eat and enjoy it. I solved the "bland" problem by making up a mix of dried chili peppers I grind up in a coffee grinder (note to self, DO NOT mix up which grinder is for the peppers, and which one is for coffee beans...:eek:). It's about 50% Habaneros, with the rest a variety of Pasillas, Chiltecpins, Japans, and Guajillos. It's as hot as you want to get things and very flavorful. I'm a junkie, I keep a small bottle of the mix in each car, travel bag, etc. I find a place that makes good tasting food and add the mix on top to make it as hot as I want it.