Any concern over it is very recent and ahistorical. Like the false etymologies of "rule of thumb", but far less well-established (and hopefully it remains poorly-established—there's plenty of justified language-policing, we don't need to make up reasons to do more of it)
Ironically your statement is an example of “political correctness gone mad” for me at least.
It’s a metaphor about shovels, there isn’t anything politically incorrect about it. Someone has just dreamed up an alternative meaning to be offended about.
https://en.wikipedia.org/wiki/Call_a_spade_a_spade
Any concern over it is very recent and ahistorical. Like the false etymologies of "rule of thumb", but far less well-established (and hopefully it remains poorly-established—there's plenty of justified language-policing, we don't need to make up reasons to do more of it)