...Bess fulfilled the same function as the hideous and sometimes obscene gargoyles found on many Christian churches. His nakedness, his ithyphallic form, his hideous face and stuck-out tongue were all meant to repel hostile forces...Bes's dancing and noisy music-making were also thought to drive away evil powers...
Bes's curious physique and the fact that his face is often shown from the front, in defiance of the normal rules of Egyptian art, have led to suggestions of foreign origin. Some scholars have compared him with the dancing pygmies known to have been imported into Egypt [possibly Ituri Forest people?]* for protective and funerary rituals in the third millennium BC. Others have suggested that Bes came from Mesopotamia (ancient Iraq). He does have much in common with the Mesopotamian lion-demon La-Tarak, who was invoked as a protector against witchcraft. - - Magic in Ancient Egypt, Geraldine Pinch.
* - my own question.
regarding origin, I found this:
http://www.crystalinks.com/egyptgods4.html
"He was not a god of Egyptian origin. Bes was described as 'Coming from the Divine Land' and 'Lord of Punt' (perhaps an area in present day Somalia - see Hatshepsut's Expedition to Punt). He was thus linked to the goddess Hathor who was known as the 'Lady of Punt' and also a goddess of music. During this period, he was given a wife, known as Beset - a female version of the dwarf god, presiding over protection, pleasure and childbirth. The two did not appear together before the Ptolemaic era."
regarding his popularity, I found this:
"Bes had no temples and no priesthood other than his oracle, but statues or depictions of the god was found in most homes throughout the land of Egypt. Although not originally one of the more famous of the gods, Bes came to be loved by the people of Egypt. It was the dwarf god-demon Bes that they came to call on for protection in their daily lives."
Sounds analogous to the modern-day "spiritual but not religious" choice made by many.