Whut? If it's users not setting up their firewall properly, it's still GFWLs fault?
There are hundreds of programs out there that will foul up with an incorrectly setup firewall, Steam will do it as well!
I'm not defending GFWL like some crazed fanboy, I far prefer Steam. However, I've never had a problem with it, and never seen an issue where the user had 0 blame for the problem.
I don't know why you keep going on about firewalls as if that's the only problem GFWL has.
My errors were not related to firewall settings.