There's never an intention to edit in such a way that the meaning is changed. The only reason to edit is to remove the bit that breaks a rule, but let as much as possible of the post remain, given that the remaining bit doesn't break any rules.
Sometimes it's only a small part of the post that needs to go, so we try to interfere with the discussion as little as possible and therefore leave the rest of the post.
As has already been said, let us know via the contact form if you feel an edit for moderation purposes has changed the meaning, and we'll fix it.
As to the rules and whether or not they are too strict - that's why we have users read and accept the rules as part of the registration process. We've chosen to stay on the strict side here, and this won't be right for everyone. Some users might well decide they want to be on a site with more lenient rules, and they can then abort the registration process and find a site that fits their posting style.
It's fine to comment on and debate post content, but not allowed to make negative comments about other users. That's not going to change.