If we take that away, the terms are as good as any, and I think it does a disservice to believe that all employees (sw engineers in this case, but in general I suspect) have equal capabilities.
In the context of my engineering experience, I consistently see ~4 strata. Not all levels may be present at a given company.
* Outstanding - has vision not only about how to do something, but why they need to be done in the first place. Open to helping others learn and improve. Has a way of being able to demonstrate that his or her plan for things is the best approach - and can accept when it's not. Is quick to learn both the internals of a system, and internalize the bird's-eye view of it as well. As such can design complex interactions between components.
* Excellent - just under 'outstanding'. This person gets things done with little direction, but gets lost in the weeds sometimes. Has a deep knowledge of the system and troubleshoots well. Can design key components of the system. Can often grow to 'outstanding' over time.
* Good - Needs direction to make the scope of problems clear. Can usually find a solution to a problem on his or her own - it may not be optimal, but you can be certain he or she will understand it thoroughly. Good troubleshooter. Can design small changes.
* Adequate - give them a spec and/or strict instructions, and they'll get the job done. Don't come to them for any deep understanding of the system - unless you have years to wait for that knowledge to seep in via osmosis or repetition.
Note that none of those mentions as criteria, "willing to go the extra mile", "works around the clock", and "buckles down and see crunch time through".
I think when you add those additional criteria is when you get into dehumanizing territory.