When any user is removed, their votes are invalidated and their posts no longer show their icon as an active member but rather a gray square showing their user number, as their account has been deleted along with their user page, meaning you cannot view their account either. When their votes are invalidated, that includes upvotes, sometimes to your own posts, which would mean the reputation you earned from them is now null and void. This information can be found here.
Your achievements tab shows all achievements and changes in your reputation, and it also accompanies the reason for your reputation's increase or decrease. Sometimes, that shows that post that earned you the reputation, but in this case, it was the removal of another user that caused the reputation they upvoted to give you to be non-existent anymore. Therefore, your account is still safe now, but your reputation has gone down. The reason is the removal of that user. Had their account still existed, you would not get any reputation change.
Now, why does it link to your profile? Because it is your reputation change. It's linked not because of the removal but the reputation.