Providing perfect information isn't always as important as providing information that's quick and easy for people to process.
Take a piece of information like '12 Apr 2012 10:09 AM PST'--there's a fair bit of mental arithmetic required to work out how long ago that was, if 'how long ago' is important to you. And it's different arithmetic depending on whether you're looking at it on the 12th of April (time zone adjustments, crossing noon)or the 14th of June (how many days in April and March). Multiply this by the number of dates on a screen, and you might end up with a lot of information noise.
A lot of the time, a quick, rough idea of 'how long ago it was' is really helpful. I wouldn't be so quick to label relative dates as stupid. Information overload is a real problem for humans, not so much for computers. It really depends on the circumstances, but for most UIs designed to be read by people, relative dates can work really well.
Take a piece of information like '12 Apr 2012 10:09 AM PST'--there's a fair bit of mental arithmetic required to work out how long ago that was, if 'how long ago' is important to you. And it's different arithmetic depending on whether you're looking at it on the 12th of April (time zone adjustments, crossing noon)or the 14th of June (how many days in April and March). Multiply this by the number of dates on a screen, and you might end up with a lot of information noise.
A lot of the time, a quick, rough idea of 'how long ago it was' is really helpful. I wouldn't be so quick to label relative dates as stupid. Information overload is a real problem for humans, not so much for computers. It really depends on the circumstances, but for most UIs designed to be read by people, relative dates can work really well.