Some people do, but most don't because they don't really care about science or spreading information, but just getting an easier way to progress in their career. And the system is gatekeeped mostly by such people, so in a lot of fields one is at considerable disadvantage if they care about things other than selfish career development.

What baffles me is why these people choose academia. It's a really uncertain and laborious way to even sustain oneself, let alone succeed.