From playing 5th Ed, I'm getting the feeling that they should have added familiar play from the start of play.
It could have been a rite of passage of some sort. I can see merits / flaws where the bond would be stronger or weaker depending on your masters teachings / your affinities.
I would even as far as stating that not having a familiar as a magus would be a story flaw or a magical flaw ( cannot / difficult binding / animal repulsion )
I mean, since you can rework your bond later on, I see no reasons why a young magus would not get his friend from the start.
I know, there is nothing that prevents a magus from having a familiar from the start but if it would have been intergrated into the caracter creation, it would have been a nice addition I think.
hmmm 6th ed I guess...