They didn't just act gay for attention. As you said, their manager did coerce them into it. But it was symbolic for them. They said it was to give younger teens struggling with sexual orientation someone to look up to, as well as encourage universal love.

That said, I ADORE their music. My favorite song by them is Loves Me Not. <3 Of course All the Things She Said, All About Us, and Stars are also amazing. :D