No, I don't think it's rude. In fact, I've received invitations to just the reception because the church wedding was just for family. Didn't bother me a bit because practically NOBODY wants to see you married except for your family.

Seriously, think about it. Haven't you ever sat thru a wedding that you know took a year to plan and the ceremony only lasts 10 minutes? What's all the fuss about? But afterwards, it's time to party!