>> Why would a newbie or someone who just wants to get analytical work done need anything beyond installing Python and doing `pip install library`? It's certainly orders of magnitude easier and faster than, say, using a C library.

Except when it isn't. For instance, because some wheel fails to build because you're lacking the VC++ redistributable (or it's not where pip thinks it should be):

  C:\Users\YeGoblynQueenne\Documents\Python> pip install -U spacy
  Collecting spacy
    Downloading spacy-1.2.0.tar.gz (2.5MB)
      100% |################################| 2.5MB 316kB/s
  Collecting numpy>=1.7 (from spacy)
    Downloading numpy-1.11.2-cp27-none-win_amd64.whl (7.4MB)
      100% |################################| 7.4MB 143kB/s
  Collecting murmurhash<0.27,>=0.26 (from spacy)
    Downloading murmurhash-0.26.4-cp27-none-win_amd64.whl
  Collecting cymem<1.32,>=1.30 (from spacy)
    Downloading cymem-1.31.2-cp27-none-win_amd64.whl
  Collecting preshed<0.47.0,>=0.46.0 (from spacy)
    Downloading preshed-0.46.4-cp27-none-win_amd64.whl (55kB)
      100% |################################| 61kB 777kB/s
  Collecting thinc<5.1.0,>=5.0.0 (from spacy)
    Downloading thinc-5.0.8-cp27-none-win_amd64.whl (361kB)
      100% |################################| 368kB 747kB/s
  Collecting plac (from spacy)
    Downloading plac-0.9.6-py2.py3-none-any.whl
  Requirement already up-to-date: six in c:\program files\anaconda2\lib\site-packages (from spacy)
  Requirement already up-to-date: cloudpickle in c:\program files\anaconda2\lib\site-packages (from spacy)
  Collecting pathlib (from spacy)
    Downloading pathlib-1.0.1.tar.gz (49kB)
      100% |################################| 51kB 800kB/s
  Collecting sputnik<0.10.0,>=0.9.2 (from spacy)
    Downloading sputnik-0.9.3-py2.py3-none-any.whl
  Collecting ujson>=1.35 (from spacy)
    Downloading ujson-1.35.tar.gz (192kB)
      100% |################################| 194kB 639kB/s
  Collecting semver (from sputnik<0.10.0,>=0.9.2->spacy)
    Downloading semver-2.7.2.tar.gz
  Building wheels for collected packages: spacy, pathlib, ujson, semver
    Running setup.py bdist_wheel for spacy ... error
    Complete output from command "c:\program files\anaconda2\python.exe" -u -c "import setuptools, tokenize;__file__='c:\\users\\yegobl~1\\appdata\\local\\temp\\pip-build-7o0roa\\spacy\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'ex
  ec'))" bdist_wheel -d c:\users\yegobl~1\appdata\local\temp\tmpypkonqpip-wheel- --python-tag cp27:
    running bdist_wheel
    running build
    running build_py
    creating build
    creating build\lib.win-amd64-2.7
    creating build\lib.win-amd64-2.7\spacy
    copying spacy\about.py -> build\lib.win-amd64-2.7\spacy

    [217 lines truncated for brevity]

    copying spacy\tests\sun.tokens -> build\lib.win-amd64-2.7\spacy\tests
    running build_ext
    building 'spacy.parts_of_speech' extension
    error: Microsoft Visual C++ 9.0 is required (Unable to find vcvarsall.bat). Get it from http://aka.ms/vcpython27
  
    ----------------------------------------
    Failed building wheel for spacy
    Running setup.py clean for spacy
    Running setup.py bdist_wheel for pathlib ... done
    Stored in directory: C:\Users\YeGoblynQueenne\AppData\Local\pip\Cache\wheels\2a\23\a5\d8803db5d631e9f391fe6defe982a238bf5483062eeb34e841
    Running setup.py bdist_wheel for ujson ... error
    Complete output from command "c:\program files\anaconda2\python.exe" -u -c "import setuptools, tokenize;__file__='c:\\users\\yegobl~1\\appdata\\local\\temp\\pip-build-7o0roa\\ujson\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'ex
  ec'))" bdist_wheel -d c:\users\yegobl~1\appdata\local\temp\tmp8wtgikpip-wheel- --python-tag cp27:
    running bdist_wheel
    running build
    running build_ext
    building 'ujson' extension
    error: Microsoft Visual C++ 9.0 is required (Unable to find vcvarsall.bat). Get it from http://aka.ms/vcpython27
  
    ----------------------------------------
    Failed building wheel for ujson
    Running setup.py clean for ujson
    Running setup.py bdist_wheel for semver ... done
    Stored in directory: C:\Users\YeGoblynQueenne\AppData\Local\pip\Cache\wheels\d6\df\b6\0b318a7402342c6edca8a05ffbe8342fbe05e7d730a64db6e6
  Successfully built pathlib semver
  Failed to build spacy ujson
  Installing collected packages: numpy, murmurhash, cymem, preshed, thinc, plac, pathlib, semver, sputnik, ujson, spacy
    Found existing installation: numpy 1.11.0
      Uninstalling numpy-1.11.0:
        Successfully uninstalled numpy-1.11.0
    Running setup.py install for ujson ... error
      Complete output from command "c:\program files\anaconda2\python.exe" -u -c "import setuptools, tokenize;__file__='c:\\users\\yegobl~1\\appdata\\local\\temp\\pip-build-7o0roa\\ujson\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, '
  exec'))" install --record c:\users\yegobl~1\appdata\local\temp\pip-ibtvwu-record\install-record.txt --single-version-externally-managed --compile:
      running install
      running build
      running build_ext
      building 'ujson' extension
      error: Microsoft Visual C++ 9.0 is required (Unable to find vcvarsall.bat). Get it from http://aka.ms/vcpython27
  
      ----------------------------------------
  Command ""c:\program files\anaconda2\python.exe" -u -c "import setuptools, tokenize;__file__='c:\\users\\yegobl~1\\appdata\\local\\temp\\pip-build-7o0roa\\ujson\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --recor
  d c:\users\yegobl~1\appdata\local\temp\pip-ibtvwu-record\install-record.txt --single-version-externally-managed --compile" failed with error code 1 in c:\users\yegobl~1\appdata\local\temp\pip-build-7o0roa\ujson\

Now that's newbie scary.

Note that this is just one case where I was trying to install one particular package. I got a couple more examples like this in my installation diary, notably one when I tried to install matplotlib, this time on Windows Subystem for Linux, a.k.a. Ubuntu, and hit a conda bug that meant I had to use an older version of QT until upstream fixed it and other fun times like that.