Okay, you want evidence? Let's play "follow the train of logic."
In official WotC D&D products, the stat blocks for monsters always include "Darkvision" under
Special Qualities if the creature has Darkvision, even if it's a magical beast. For example, in RttToEE, the Giant Frog is a medium sized Magical Beast, but it still says "Darkvision" in the SQ section. Even though it's assumed Magical Beasts have Darkvision, they still mention it, just so you know
for certain.
Now, in that same product, they have a stat block for Sebbekai. Who's Sebbekai? A cat familiar to a Wizard. What does it say under SQ? It says "Improved Evasion, Speak with Spugnoir (his master), Speak with Cats."
It includes stats for other familiars as well. Kubo the toad. Jolana, a fiendish bat servant of a Blackguard. (Not a familiar, I know, but still.) In all cases, it lists special qualities and special familiar benefits. In
no case does it mention Darkvision. Thus providing evidence that the wording in the Player's Handbook is poor and confusing, but proving as well that familiars were not intended to have Darkvision.
Unless you want to convince me that you know the rules better than Monte Cook does.
