Destination wedding selfish?

I see people saying that on here and I don't get it. Why is it selfish? My family lives all over the country, so many people would have to travel to come to a wedding regardless of where it is. We are having our wedding in St Thomas and paying the airfare and hotel for our immediate families (12 people) and hosting a dinner the night before and a reception afterwards for everyone coming. There is no bridal party who would incur extra expenses, and so far, 35 people have called us to say they're coming, though we haven't even sent out a single invite! (We plan to do that this weekend) Obviously they really want to come...we are also hosting a clambake in our hometown for about 200 upon our return so those who want to celebrate, but not travel, can come and have fun. How is that selfish?