"In my experience, managers’ responsibilities were … - Communicating messages from top to bottom - Settling disputes - Managing careers - Keeping their teams motivated and happy - Shielding their teams from things they didn’t think they needed to know"
I think that's a pretty narrow definition of management, esp. things like "communicating messages from top to bottom".
While I don't disagree with the fact that a significant component of management, esp. large parts of middle management, can be done away with, I don't think any reasonably complex and growing organization can do away with management altogether.
A great manager (who may also play a part as an individual contributor) can channel & amplify an organization's creativity and innovation. S/he will also ensure there is an alignment b/w the organization's high level strategies and the individual contributions being made.
Much as we'd like to think that tech workers are unusually self-motivated or that online tools can fully substitute people management, in my experience neither are the complete truth.
Further reading:
- How Google Sold Its Engineers on Management: http://hbr.org/2013/12/how-google-sold-its-engineers-on-mana... - The Flattened Firm—Not as Advertised: http://hbswk.hbs.edu/item/7000.html - Be a Minimally Invasive Manager: http://blogs.hbr.org/2013/10/be-a-minimally-invasive-manager...
Fair disclosure: I'm an MBA...biases, warts and all.