I am aware that they probably fund terrorism as part of their Death to America stance. But the continued US sanctions are not going to help if we refuse to reward them for correct behavior. They agree to deal, inspections, winding down nuclear facilities, and we respond with erratic behavior. I wouldn’t be suprised now they will increase their support of enemies of the US since we are forcing them to be our enemy. And the US has never imposed sanctions on countries with poor LGBT rights (having itself only recently accepted LGBT people). We impose sanctions to get what we want, not protect human rights. We deposed their democratically elected leaders for less than noble reasons.
Yeah, Iran probably (but who can say for sure) funds terrorism with that whole Death to America thing. And gay marriage was only legal in the US in 2013 or whenever. So not much difference between that and hanging people. Putting it that way, I can see your bafflement.
I think if you believe the US is sanctioning Iran because of their gay rights record then that would be pretty naive. It's all about power and politics. We didn't depose their democratically elected leaders for their benefit, that's for sure.