I think next time you get "forced" into taking pics for pple who are close to you (read: take advantage), and seeing as you are fueled more by passion than money (that's good, btw!) tell them you will shoot for FREE, but you guarantee nothing. shoot for yourself and your passion, and these beautiful images (if any) can be SHARED with them. Specify that they should also really engage someone who does this regularly, and that you will be taking alternate angles that the pro might not be able to take. You mentioned that they "can't be bothered searching, and too expensive to engage another photographer" to which you need to stress your point, there could potentially be ZERO photos for something they paid ZERO dollars for. potentially. How you want to sugar coat that with PR polosoh, up to you.
Trust me, alot of times when I am the main photographer, I wish I could run to the other corner of the room where a kid is craning her neck to see the bride instead of shooting say... the march in?
Of course i also agree with many of the responses here, don't like weddings then don't shoot, whether paid or not. i think quite common sense. =)