They are invalid in a discussion about IE9 developments because they aren't about IE9. They are valid in a discussion about web development in general... except they are arguing against your citing 'netscape' and 'holding back web development' because this blog is about MS not holding back web development and not destroying a competing browser. In other words, Microsoft has moved on from those (e.g. this page) so those aren't good support for your complaints anymore.
People in this page are saying bad things about Microsoft, about their javascript interpreter speed, their lack of canvas support and rounded corners and font handling and they aren't being voted down. Any guesses why?
I am an MS apologist. I have worked with their stuff for the last six years and find it (mostly) better than I previously thought, and not deserving of quite as much of the mudslinging as actually happens online.
Islam
Don't know anything much about Islam and couldn't give two whoots. Particularly don't want to discuss religion or country/world politics on HN, even more so in a thread about an IT topic. By the way, I also don't want to discuss dishwasher detergent, pie recipes, good books on optical illusions or how to build a canoe.