I have anecdotal knowledge of a number of men who made sucky husbands and great dads. It's not that strange.

I really hope you're right and he's written as not the biological father, but the Dad. It just would seem more relatable to me, even though my dad was more of the once-a-month-parent/more-like-an-uncle kind.

Can't deny Moranis fits the physical stereotype of a geek to a tee. He is more adorable somehow than others with stereotypically geeky builds, though, and I can't really put my finger on why. He just is.