Then you also have the ambiguity of what is considered human readable, is an xml document human readable? Http headers? File paths? Urls? Is a programmer considered human?
Smells like non binary serialization format or something alike, which is usually a code smell. It's convenient the first 2 weeks but once the project grows you need a more strict schema and once you have that you might as well use a serialization library which might as well have a binary serialization backend.
Why would you not? E.g., you use pandas and columns all have names. Colors are typically also strings, etc. Thus you would often do things like
grouped = df.groupby(['foo', 'bar'])['baz'].mean()
grouped.plot(color='red', title="User-facing title.")Then yes, there are valid uses, especially in ad-hoc scripts. Column names and dictionary keys are one of the gray zones, though again, in my experience once your project grows these are also usually better to code generate from your db schema or serialization protocol; either complete data structures, api-functions, or just a list of constants. Anyway, my point is not to ban strings entirely, it's to question what we use it for. If you use strings as data/identifiers so frequently that you need a special convention for them something smells quite fishy.
[0] Auto complete = More accessible form of documentation. Before someone starts screaming that i'm stupid for "ignoring documentation".