I find this to be the case for most "spicy" things targeting a western market. Firehouse Subs has a hot sauce bar where they rate the spiciness from 1 to 10. Normally I don't bother with it because the ones at the higher end tend to either be some spicy vinegar variation (ugh no thx), or pineapple based, which I'm usually not in the mood for.
Last time they had an 8 that wasn't either of those so I asked them to add a line to my sub as they made it.
It's like their 10 was targeted at jalapeno spiciness, maybe cayenne. The 8 did add some heat, but it was where I'd call it a medium, and a mild one at that.
Should use a logarithmic scale I guess. Just frustrating that spicy stuff always seems to be marketed for people who don't really like spice. The less generous side of me thinks it has to do with people wanting to act tough but are actually whiny losers who thinks it's the seller's fault they can't handle the heat they wanted to show off handling.