Well, Snowflame is more "fun" as a villain, and he had his own personality, raving about how he's powered by cocaine, while I'm pretty sure that Hemo-Goblin was more of a barely speaking monster being used by the white supremacists. Plus the HIV storyline, while probably well meaning by the writers, was not done well and so was mostly forgotten. The New Guardians writer, Steve Engelhart, was definitely trying to talk about (at the time) modern real world issues in the book, but didn't really hit the mark. For example, there is a reason very few people know about Extrano, even though he was DC's first openly gay character: he was hugely stereotypical, and just not a great character. Snowflame just happens to be the perfect blend of wacky idea, memorable appearance, and pure 80s craziness, he couldn't have been conceived in any other decade, so he's very memorable for a one shot villain from an obscure comic book mostly filled with Z-list characters.