How did "Matron" and "Patron" come to mean different things?
The entry for patron primarily denotes patronus (protector) as the origin of patron, and patronus as a derivative of pater (father), which wikitionary confirms. The connection then becomes father -> protector -> supporter -> paying customer, which follows a relatively logical progression, and explains the many different definitions that the word took on throughout history, as you listed them.
Mater, on the other hand, apparently did not have the same connotation of being a protector, so it became matrona, which simply means "married woman". This led to a far less diverse evolution of its meaning, as is evidenced by the few, similar definitions for it.