I think the main distinguishing personality trait between developers and designers is that designers actually enjoy the exploration and experimentation process of design. Developers can do it but they clearly don't enjoy it.
The same could be said for many designer's view of development. Even if they are capable, they clearly do not enjoy spending the majority of their day solving problems, chasing edge cases, and learning more languages/paradigms/patterns/etc.
And designers should take a more active role in being aware of the limitations of the systems they are designing for. I've worked on a number of projects where feedback from developers about things the designer is obviously not aware of, from scheduling and effort to technical constraints, were met with derision and holier-than-tho attitude.
The article is advocating for working together, not at loggerheads with each other.
I think word "design" is a bit overloaded here. There is a difference between what "design" is for designers (like Jonathan Ive) vs that for the developers/engineers. I am guessing what article is saying is the former one.
Having said that the line is far more blur than what the article is saying.
If I'm left to guess at what you want, it'll be a waste of time because you're not happy with my interpretation in many cases.
Respect me as a developer by doing your homework and telling me what you need (please!).