Everyone's opinion should hold equal weight. I can agree with that. Your opinion on an issue shouldn't affect the course of someone else's life if that issue has absolutely no affect on you. As an example, if someone wants an abortion and you're against it, why should you're opinion outweigh theirs? Whether that person gets an abortion or not has absolutely no consequence to you (whether you say it does or not). Is your stance more important because you are you?
If you want to get into an argument that abortion degrades the moral integrity of our society, well that is a whole other issue.
Anyway, I'm just trying to look at this issue from a humble perspective. I think people should ask themselves why they think they should be able to tell others what they can and can't do.