Mixed Message

For at least the past 30 years we've been hearing that marriage is not necessary, that it's just a piece of paper and that it is commitment to each other that keeps partners together.

Now, it is urgent that gay and lesbian people be allowed to marry and the president agrees.  So too, do the many heterosexual Hollywood couples  who do not believe it is necessary to marry and have that piece of paper that proves their commitment.

Could someone please explain to me why it is necessary that gay and lesbian couples marry while it is not necessary for heterosexual couples? 

We're definitely getting mixed messages.