It seems odd to me that people are ranting that Microsoft has included the Yomi fields.
Microsoft is simply conforming to the industry standard fields that have become common over the years as "contacts" systems have been developed by various companies (Microsoft, apple, google, yahoo, twitter, facebook, ...).
Yes, it might be nice to have more flexibility such as user defined fields. But at this point, imagine the problems a person would then have when trying to import/export their contacts amongst the many various providers like the ones mentioned above.
I agree that some better UI choices could be made to make fields more comprehensible.