There's a big difference between legality and enforcement. Drugs (including weed) are illegal in Thailand. But you'll find weed lounges on several islands. Just don't carry anything outside. Prostitution is illegal in Thailand. I'll let that stand on its own. I'm not equating prostitution to being an LGBT individual - merely point out that just because something is illegal doesn't mean the government is up in arms chasing individuals who even "feel" different. Tourism brings in a f-ton of money to all these economies, so they let foreigners be unless the said foreigner is working extra hard to rub it in their face and trying to "de-legitimize" their culture somehow - however bigoted the culture might be. And as you pointed out, LGBT have strong legal protections in the USA. Yet it would be ridiculous to say that LGBT individuals are safe everywhere in the US. To say that the US is somehow a safe haven for LGBT merely because of "law" is insane to me. Culture matters more and there's plenty of places that could do WAY better in the US. I find more parts of Thailand to be more tolerant to foreign LGBT individuals than the US even if they don't enjoy the legal protections as they do in the US. Not just Thailand - Sri Lanka, Cambodia, Laos, Vietnam, Japan, Hong Kong, Taiwan, South Korea all do better in my opinion ie you aren't at risk of being pummeled by someone random. And yes I have met LGBT individuals in China and Russia as well and they managed just fine.
Having said that, to each their own. For some the prevalence of bigotry (legal or otherwise) and hatred is an admissible risk of traveling and they learn to navigate that space. For others, maybe not.