It's by design of the entire site/network.
Basically, any edits have to be made, or be approved by, "trusted community members". If it gets through, and you don't agree, roll it back and move on.
Who makes sure that proposed edits are good?
Any user can propose edits, but not all edits are publicly visible immediately. If a user has less than 2,000 reputation, the suggested edit is placed in a review queue. Two (three on Stack Overflow) accept or reject votes are required to remove the suggested edit from the queue and either apply the edit to the post or discard it. Users with more than 2,000 reputation are considered trusted community members and can edit posts without going through the review process.
What happens if someone suggests a bad edit?
If a user without edit privileges proposes an edit that does not comply with the guidelines above, it is ordinarily rejected in the review process. Even if a bad edit is applied to a post, other users will generally fix it. Users with sufficient reputation may elect to roll back the post to a previous version (by viewing the revision history of the post and selecting the version they would like to display).
Additionally, any user who submits many rejected edits will be banned from suggesting further edits for 7 days.
At just 2k rep, you get the Edit Questions And Answers Privilege
What is edit questions and answers?
We believe in the power of community editing. That means once you've generated enough reputation, we trust you to edit anything in the system without it going through peer review. Not just your posts—anyone's posts!
When should I edit posts?
Any time you feel you can make the post better, and are inclined to do so. Editing is encouraged!
Anyone below 2k rep can Suggest an Edit, which is then reviewed by people who have the above 2k privilege
Reviewing suggested edits
In addition, users with this privilege level can also begin reviewing suggested edits (which previously you would have had to suggest). These edits remain in a pending state until they get enough votes to either approve them and make the edits take effect or reject them and discard the edit.