I've found another reason why JWs are discouraged from reading the bible alone.
13 Yet within three days shall Pharaoh lift up thine head, and restore thee unto thy place: and thou shalt deliver Pharaoh's cup into his hand, after the former manner when thou wast his butler.
18 And Joseph answered and said, This is the interpretation thereof: The three baskets are three days:
19 Yet within three days shall Pharaoh lift up thy head from off thee, and shall hang thee on a tree; and the birds shall eat thy flesh from off thee.
20 And it came to pass the third day, which was Pharaoh's birthday, that he made a feast unto all his servants: and he lifted up the head of the chief butler and of the chief baker among his servants.
Pharoah's birthday was chosen to decide the fate of the butler and chief baker. A feast was held for all all of the servants, not as a day to give gifts to Pharoah. The birthday was a great day for the butler because he was innocent. The chief baker (who was guilty) received his just due. I don't see this as a good reason to outlaw birthdays.