I suspect that ego has a truly valuable role that we do not always realize, because of the times that it gets in the way.
Like everyone, I often fight personal dragons. For me, these take the form of self doubt, usually regarding personal appearance, or sometimes the fact that my thinking does not fit in with my peers. I am not particularly weird looking, or weird thinking. But, let me put it this way: I only get a dollar for my presentation to the outside world. So, like the essayists, I am quite willing to think that I need to change something in order to fit in.
But ego, in the form of confidence in a particular idea, or in a track record of solving problems in creative ways, can help me to get through these problems and present a better argument for whatever thing I need to get done.
I think the real problem here is that the tools we have bred into us, by the billion or so years of selection, are not always perfect for the tasks that we now encounter daily. Engineering and maintaining code are the problems we are talking about.
We are crossing the bridge from gene-based behavior to meme-based behavior. We've been doing this for awhile now. Remember, before we lived in cities, or even villages, we sat around in caves. Many behaviors must have taken place that would get you arrested by the city police now, but in those days, they were decided by physical strength and cunning.
Physical strength and cunning are still useful, but civilized people had to realize that not every problem was a nail that required those hammers. Laws substituted, first religious, then civil. Then came guilds and professional organizations, which taught ways of the profession, and craft to obviate the reliance on laws. Then there are organizations like companies that layer their own way of doing things.
I suspect it could be argued that arguments peel back the layering of social nicety - a reverse recapitulation, a mirror of how we develop. In a well-formed argument (the worst kind you could imagine), one party starts perhaps by kidding another, then perhaps one questions the professional wisdom of another. Then somehow the issue of legality, then morality enter in. At worst then, it could become a sheer fight for life by one in response to the other. As bad as it sounds, those tactics get things done. If someone spits on your doorstep, you proabably don't want to spend much time explaining to them why it is not a good idea.
On the other hand, new ideas, I mean really new ideas, don't come from reliance on codified knowledge.
I think the fundamental difference here is in how one reacts to the decision of whether to reach through the layers of mores, laws, brute force (let's call that reaching back) or reaching forward into new, uncharted territory. Reaching back only requires ego. Reaching back very far may require large, or combined egos.
Reaching forward requires putting all those preconcieved systems away momentarily, and modeling the new world lines in your mind. Let's call this true thought (I call it true to distinguish from what often passes for thought, usually some kind of reaching back into professional knowledge or preconceived ideas. If it seems like I am sneaking in a subliminal direction, please call it some other kind of thought). In true thought, ego has no place, but as soon as the thinker begins to classify and codify any new insight, the thinker may need ego to have confidence in the idea and to communicate it before it is lost. Reaching forward, one must tread between egoless and ego states.
I think that Tilly's focus on learning and meta behavior is good to uncover more about reaching forward. But, some ego is required in either direction. I think that code writing requires a lot of reaching forward, and a little reaching back. Other activities, like collaboration, code documentation may require somewhat less reaching forward (but they still require it) and more reaching back.
I suspect that wisdom is a synonym for not having to reach back very far.
The way I look at it is that I should never stop trying to strive for pure thought, and I should try not to interfere with those who have lately succeeded in applying pure thought to the benefit of me and other beings like me.
Now, where's my dollar?