I was at Harvard when Facebook launched. Within days, it had a huge, highly engaged userbase which it never lost. HouseSYSTEM, in contrast, never took off. Why do you think that was? I'd argue it had a lot more to do with the differing design and motivation of the sites than press coverage. Students signed up to The Facebook because it was cool, viral, and not officially sanctioned, not because they read about it in the Crimson. HouseSYSTEM was none of those things.

You seem to think that Mark should have (then) asked you to help with Facebook or (today) acknowledge that he learned from HouseSYSTEM. I'd suggest that Mark's heavy use of HouseSYSTEM showed him mistakes to avoid and thereby encouraged Facebook's adoption. Maybe he thought you were too invested in the choices you'd made with HouseSYSTEM to start fresh.