Why is craft setup telling me to do stuff it could do itself?

[Boylan, Ross]

I just installed craft on a Windows 10 system, and got warnings like this:
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Execute: J:\Programs\Python39\python.exe J:\CraftRoot\craft-master\bin\craft.py craft
Found "sh" in your PATH: "J:\Programs\Git\usr\bin"
This application is known to cause problems with your configuration of Craft.
Please remove it from PATH or manually set a value for PATH in your CraftSettings.ini
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Since craft knows the path is a problem, why doesn't it just filter it out, or at least write the configuration 
Info to do so?  In particular, at the bottom of craftenv.ps1 looks as if it completely clears the environment,
replacing it with the output of CraftSetupHelper.py.  The latter is the, or at least a, source of messages such as those above,
from checkForEvilApplication().

One problem with writing a PATH into CraftSettings.ini is that it requires a fixed string. I don't think one can put code there
that will strip out a particular entry from the current environment.  So if the environment changed after setup (e.g., from 
a new release of Visual Studio) the craft environment would get out of sync with the main environment.

Another warning raises some related issues:
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executing command: J:\Programs\Python39\python.exe -m pip install --upgrade --upgrade-strategy only-if-needed --user pip
Requirement already satisfied: pip in j:\programs\python39\lib\site-packages (21.1.1)
Collecting pip
  Using cached pip-21.1.2-py3-none-any.whl (1.5 MB)
Installing collected packages: pip
  WARNING: The scripts pip.exe, pip3.9.exe and pip3.exe are installed in 'C:\Users\rdboylan\AppData\Roaming\Python\Python39\Scripts' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed pip-21.1.2
WARNING: You are using pip version 21.1.1; however, version 21.1.2 is available.
You should consider upgrading via the 'J:\Programs\Python39\python.exe -m pip install --upgrade pip' command.
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First, if it knows something should be on my PATH, why doesn't it just add it?
Second, why does it tell me I have successfully installed pip-21.1.2 on one line and warn me I'm using 21.1.1 on the next?