It's more of a public record to help track you down.
(This is US Civil Law only, other places are different)
In order to object (and really most of that is in the hands of the judge) they have to do it by claiming that the name change name change is not for a fraudulent or other illegal purpose, such as evading a lien or debt, or for defaming someone. Or if the name change is for "frivolous" or "immoral" purposes, such as changing one's name to "God", "Superman", "Copyright", or "Delicious." Also, one cannot choose a name that is intended to mislead (such as adopting a celebrity's name), that is intentionally confusing, or that incites violence; nor can one adopt, as a name, a racial slur, a threat, or an obscenity. (mostly from wiki)
And, before you can object you have to have what the law calls 'standing' that is, you have some vested interest in the matter at hand. No one can just walk in off the street and object.