My theory on this has always been:

First spider morph produced was the Pastel X Spider cross, and because it was bright yellow and black the breeder thought it looked like and therefore named it Bumblebee.

Other spider breeders thought the name was very cool and decided the best way to shorten the names of a morph containing the spider gene was just to tack the word "bee" onto the end.

So each time a new spider morph was produced, they gave it a name that included bee. It seems as though the tradition continues today.

Gale