Rules often change to reflect current trends (not always a good thing). It has now become more acceptable to write "businesses" purely because of asthetics and to reflect the more common pronounciation.
Regarding people's names, if the name is naturally spelt with an 's' at the end for example "James", then you only put an apostrophy ( ' ) without another "s" so the plural
Hi Zebedee, and welcome to the forums. Can you cite some examples used in reputable publications that use businesses without the apostrophe that indicate a plural possessive? That sounds extremely odd to me.
On the issues of James's versus James', and other proper names, that certainly does vary whether that "extra" s is used, but for a generic noun like "business" I'm astonished t