There's also the urge to write things in an affected way because it sounds more refined.
The Rockefeller family has been plagued by this for generations. People thought that the pronunciation sounded lower class. As a result, letters to them were often addressed to the 'Rockerfellow' family. That makes them sound like a group in 1960s London.
A similar thing happened to the term 'tuxedo'. In the 19th century, an enclave of wealthy people developed on the New York -- New Jersey border around a picturesque area known to the local people as Duck Cedar Pond.
To the new people building their mansions the term sounded uneducated. Thus, 'Duck Cedar' became 'Tuxedo'. If this hadn't happened most men would be wearing Duck Cedars to their Weddings.