There's truth to this but at the same time I am one of those who bought FQHH and regretted it and I did spend some years trying to make it work. I don't like the leather's qualities or how it feels on and if you are in a warmer area it is almost never wearable. I suspect FQHH is most successful in cooler places but personal taste also plays a role. I've collected hand crafted leather jackets for over 30 years and 3oz leather, particularly FQHH has never appealed to me.
I think you're right - I can't imagine trying to wear the full horse any time before late September or after mid-April, but after that it's a question of what you feel comfortable with.