I think every one of us who has had (or is planning) a DW has faced this in some way, shape, or form. Our thoughts on it were we know people won't come, we won't be offended if you can't come, we'd like you there, but this is how it's going to be. There were several very important people who were missing on our wedding day, but i wouldn't change a thing about that day. It was about US, not some random guest who complained alot.
I wish I could make you feel better about this. People just like complaining. At least you recognize that any place you'd have it, people would be complaining. Remind them that it's YOUR wedding, not theirs.