I would argue that in fact you do need a critical mass of ego throughout the ranks of engineers in a large organization. An engineering culture where engineers don't care inevitably leads to abdicating responsibility for overall system health and even data/workflow correctness as PMs attempt to steer the ship without understanding the implications of what they are asking for. Once this has gone on for a while, the system will be so intractably broken, and the dead sea effect will have caused such a brain drain of all those capable of fixing the problems, that at some point there's no economical path to restoring the software systems to a healthy and maintainable state. At that point you might as well just call in the private equity guys and figure out how to extract maximum cash out of the business as it stands, because any code change becomes more likely to break more things than it improves.

So yeah you need ego. That said, it must also be tempered with the reality of needing to compromise enough to satisfice all stakeholders (including both technical and business stakeholders of all the different flavors). The beautiful thing about software engineering though, is there is a reasonable amount of objective facts, metrics and tradeoffs, that given a critical mass of sufficiently skilled and mature engineers, common ground tends not to be too hard to align on. Or at least, far easier than to get a non-technical stakeholder to understand the long-term implications of a bad decision.

The ego is, indeed, referred to in a negative sense because most people do not sublimate it to serve the group. It's natural state -- and, therefore, our natural state -- is to be selfish to oneself and one's in-group.

There are 19 pairs of vice/virtue pairs in the ego. We can only decrease our ego's vice-eous tendencies by increasing our consciously manifesting compassion to everyone we encounter. It also helps to contact our Creator and ask for guidance. It awaits us in Its Unfathomable Lonliness to beseech it for help to begin and then see out the complete transformation of our ego into a selfless, servant of the happiness of others and the societies/cultures we inhabit.

That Path of Loving Service is the key to happiness, and is the opposite of narcissistic attitudes and bahaviors.

There is nothing mysterious about the ego; it's just that willful ignorance is one of our heart's vices, and its purpose is to deny that each person's ego transformation is not only possible, but the source of joy and community uplift, and is our free will to choose love or any of its many selfish opposites.