It has a value in making businesses aware that production code has an operational cost just to keep it "alive". And it's useful for tempering junior developers who haven't yet absorbed principles like KISS and YAGNI.
But it fails to factor in the relation between code and an organisations ability to make (or save) money from that code. For example the capabilities of your code may be a competitive edge for your business. 10 lines of code which uses CPU and memory inefficiently may end up being more expensive than 1000 lines of code which uses CPU and memory _efficiently_ and leads to lower infrastructure costs as usage grows.
As far as I'm aware the term goes back to 2007 - https://web.archive.org/web/20070420113817/http://blog.objec... - a time where businesses hadn't really understood how to manage software based businesses, so it was a useful concept to help management become more mature about how they think about software.
But these days knowledge of how to run software based businesses is far more widespread - we don't need to simplify our thinking to "code is a liability".
There is a difference between code and a liability. If a business could wave a magic wand and instantly remove all liabilities from the balance sheet, it would do so without question. They would not, however, do that for code (or the business would collapse).
Part of your job as a commercial software engineer is to maximize the balance sheet of the projects you work on.
Sometimes the simplest overall solution isn't so simple in isolation.
Linux could be considered simple given the problem it's trying to solve and yaml complex.
For example they might think that in a mixed-paradigmatic language the "pure functional approach" is more simple even if it introduces more indirection and requires a deep understanding of various more advanced language constructs(*).
Or that the simplest explanation of monad is the one based on PL-theory instead of an explanation based on terms people without an scientific-PL background are more familiar with.
Or people which think that writing down things in predicate logic is just way simpler then writing them down in English (well, I guess thats somewhat me).
None of the "I find this is simpler" points I mentioned are bad, but not realizing/accepting that what is simpler for you isn't simpler for others is the problem.
It's really hit or miss when it comes to having any impact.