Declining RSVP?

Well, we are having a destination wedding, so the majority of the RSVP's have been "decline". Of course, there could be some validity to what you are saying in that mine are due next week and we have received less than half back. One of our theories is that people feel bad to decline so they aren't sending them back at all. I wish people would just be honest, we aren't going to be mad at anyone who can't come. I'm more mad that they aren't letting us know!