It's surprising how few managers value objective estimation. But the problem I suppose, is what it does to the working relationship the rest of the company has with their software development team.

Basically, to allow a team of developers such an 'indulgence', every worker in a given business, including senior managers, have to accept that all interactions with the development team, are led by the development team.

That takes a lot of trust, and you'll rarely find that level of trust outside of a startup.