Bourbon is much more individualized by barrels and recipe than heat and humidity.

Yeah, it plays a role, but even some of the best pro tasters out there can't reliably blind pick bourbon by location, and there's a ton of difference in environment between just Kentucky and Tennessee's averages in heat and humidity. When you start breaking it down even further, like between something from the mountains vs something further inland, those variances get higher.

The average drinker though, they'd have trouble telling the difference between Kentucky bourbon and crown royal to begin with. Which isn't contradicting your point, it's more a general thing about how little the details matter to someone that isn't into a specific type of liquor.