The outdated information is still useful to the credit agencies and for identification.
If you have ever run across an instance where they ask you to tell them which of the following streets did you own a property. They were using the historical info in the file to make sure that you were the person that was reflected the file.
The different spellings may be a different matter. If the person has the formal name of William, but may have info as Bill, Will and Billy, that should be reflected in the file. If they changed their name when they got married, both names should be listed. But if you never used that name, the record needs to be corrected. And by correct I don't mean just change the name.
Now if the record in the file regardless of the name , address, and phone number is not yours that has to be changed. All credit bureaus have procedures in place for you to challenge the info. This is one reason why you should check your file every year.