It's not so much that it seems quaint, it's that we are accustomed to short-term, transactional, Wall Street thinking from companies like Google.

For very good reason, because that's exactly how they behave in all other areas. The question remains, why do they appear altruistic when it comes to sharing papers?

I find it hard to believe that it's actual altruism. It's far more likely that it's transactional behavior that just appears altruistic from the outside.