Ya know when you think about it, Sirius was really only in maybe two books total. He has a decent role in OoTP but his appearances in PoA ad GoF only really add up to one book's worth of character as far as I'm concerned.

And then he dies. We're supposed to be oh so attached to this guy we have barely spent any time with.

This is made even more laughable in the movies. I'm watching RiffTrax'S Goblet of Fire now and I had totally forgotten they took out what little presence he had in it to begin with. So now we're supposed to care about a guy who was in 1.5 books at most.

What I'm saying is that Harry has no reason to feel close to Sirius at all in the movies.