Correct.  There might be some gay couples who want a church wedding but many probably don't want that.  Lots of straight couples would prefer destination weddings or weddings where they have control over their ceremony.  There is lots of frustration among straight couples about the restrictions on the Catholic ceremony - i.e. no custom vows, restrictions on music and readings, no additional personal touches (i.e. not allowing a special poem), etc.  I've even heard of issues using things like the wedding march.

Many gay couples would be fine if their marriages weren't treated as "sinful," if they weren't denied the Sacraments, and if they weren't fired from their jobs.  Oh and if the Catholic Church stopped campaigning against civil marriage.