You may have noticed that I Ninja Edited my post a few minutes ago to add:
"If anything they're just less worried about it since they have the most market share."
I think that's why they're slow. They don't have that much incentive to be faster. If Firefox hadn't taken so much market share from IE I doubt there would be many people working on it.
My Mario Kart Wii friend code: 2707-1866-0957