The main reason that searching by subject is recommended for searching for information about a particular person is that the Uniform Name for people also applies to subject searching. So, just like for authors, if a person's name can be spelled in multiple ways (Mao Tse-tung / Mao Zedong) or if they go by a pseudonym (Samuel Clemens / Mark Twain), the entries will be linked.
Here is the Uniform Name of Bill Gates. The catalog reveals that there are 13 books in MUSCAT about Bill Gates.
