It’s probably my lack of imagination, but I never even considered that Bert and Ernie were in a gay relationship until I read some references to that possibility a few years ago. I can see why gay men might want to think that and also how the two muppets fit certain stereotypes about gay couples, but I don’t know that it’s cool to appropriate them as symbols of the struggle for gay rights. It’s not that muppets shouldn’t be sexualized. After all, Miss Piggy and the Swedish nurse are intentionally sexualized. But Bert and Ernie are not intentionally sexualized. They appear to me to be more like Felix Unger and Oscar Madison than a couple in physical love with each other. They are close friends that suffer compatibility issues. They drive each other nuts but get along anyway. And I think that is the point that the creators wanted to convey to young children.
Still, there is something silly about people arguing about muppets, teletubbies, and other made-up characters.