On the idea of replacing ones self with a shell script, I think there's nothing stopping people (and it should probably be encouraged) with replacing ones use of an LLM with an LLM generated "shell script".
Using an LLM to count how many Rs are in the word strawberry is silly. Using it to write a script to reliably determine how many <LETTER> are in <WORD> is not so silly.
The same goes for many repeated task you'd have an LLM naively perform.
I think that is essentially what the article is getting at, but it's got very little to do with MCP. Perhaps the author has more familiarity with "slop" MCP tools than I do.