I think if time on page and average session metrics suggested that's what people wanted, that's what we would see. It's like complaining about how the news reports on inane stuff.
Sounds like a case of bad metrics. Time on page when your goal is to get people to use your software/framework isn't meaningful. In fact, I suspect better communication leads to shorter times.
Similar idea with news. The objectives of profit and conveying meaningful information aren't necessarily aligned.
Disregarding the subjectivity of 'meaningful,' the advice 'know your target audience' is good from both a product design and marketing presentation stand point.
I think that for both examples, having people's attention is a precursor to doing anything else. That's just my intuition though.
Maybe it is possible to have a landing page that people leave much more quickly but that is more successful. Maybe it is possible to keep your audience informed without them watching for very long.
You are assuming they have done analysis and A/B testing. More likely they simply copied the approach of consumer products, without thinking too deeply about the fact that developers are their only users.
Similar idea with news. The objectives of profit and conveying meaningful information aren't necessarily aligned.
Disregarding the subjectivity of 'meaningful,' the advice 'know your target audience' is good from both a product design and marketing presentation stand point.