Not sure one follows from the other.
I agree that you might as well give up on tweaking your system to achieve greater fidelity (the “fi” in hi-fi), as modern equipment is so good any tweaks are unlikely to produce improvements. Not sure that’s the same as giving up on hi-fi… you can still enjoy the music!
But the term “snake oil” has a long and notorious history as both a description and a chronicle of the various schemes perpetrated to sell worthless “improvements” in health to incautious consumers. Often these were in fact addictive or even poisonous, instead of helpful. Clearly there’s a lot of that going on in the audio business, selling worthless or even counterproductive “tweaks” to clueless or over-enthusiastic do-it-yourselfers. For instance, this poor guy.