As an Engineer, I take exception to that statement. Maintenance Engineers and Design Engineers are different animals. One is happy doing one thing, and the other is happy doing the other.
Of course, maintenance is a much longer task in any given project, which explains the percentages of work splits.
There are obviously far fewer design Engineers than maintenance Engineers.
In fact this whole story has a problem in that it is misrepresenting basics like those, to try to convince us that innovation is somehow a bad thing, and things should be allowed to stay the same.
In truth, nothing stays the same, and we need to innovate to keep abreast of it.
The only solution to the current world problems is innovation.
We need to create a new economy, which obeys sound engineering principles and the laws of nature, as opposed to the profit driven political animal that is the old economic system.
Humanity has a deficit with our planet, which demands we put back in what we take out.
That cannot be done using the old economy of scarcity, because the true wealth of the planet is directly linked with the quantity of photons landing on it, and that does not equate with what we call wealth in the old system of controlled scarcity.
Now we see free money is needed, to tide us over until we can balance up the deficit against the free energy of the sun, which we need to plug into at the earliest opportunity, instead of trying to balance the deficit by some kind of human-to-human debt.
That is a very simple analysis, though it maybe took a long time to realise it, due to some wierdness in human nature.
Now it is known, we have no excuse for not following it.