I don't really agree with that unless you redefine the ego as being synonymous with 'being egotistical' or 'sinful pride'. You need a sense of self to feel pride and something more than base passion.
For practical purposes, if you don't acknowledge how good and bad behaviors can both spring from the same base emotions/thought processes then it's harder to grow out of the bad behaviors. You need to be able to reframe how the ego interacts with your work, not just try to kill it off.
For practical purposes, if you don't acknowledge how good and bad behaviors can both spring from the same base emotions/thought processes then it's harder to grow out of the bad behaviors. You need to be able to reframe how the ego interacts with your work, not just try to kill it off.