So what? Most people don't care about battery, so let's just have a crap battery? That argument would work, if Apple released a super light laptop with a tiny battery, specially made for "most people who sit at their desk".

No, people do care about battery life. That's where Macs excel. (I'm saying this as a Thinkpad user, where getting 6-8hrs of battery is doable, if you don't do anything on the laptop).