Pip installs console_scripts entry point even when required extra is not present

Question

Given this fairly minimal setup.py (greenlet and gevent are just placeholders for arbitrary dependencies)

from setuptools import find_namespace_packages, setup

setup(
    name='foo',
    version='0.0.1',
    platforms='any',
    packages=find_namespace_packages(),
    install_requires=['greenlet'],
    extras_require={
        'bar': ['gevent']
    },
    entry_points={
        'console_scripts': [
            'foo-script = foo.script:main',
            'bar-script = foo.bar:main [bar]'
        ]
    }
)

with foo/script.py containing this

def main():
    try:
        import greenlet
    except:
        print('Dependency missing.')
    else:
        print('Found dependency.')

and foo/bar.py containing this

def main():
    try:
        import gevent
    except:
        print('Dependency missing.')
    else:
        print('Found dependency.')

I would assume that, when I run pip install ., it would just install foo-script and only install bar-script if I did pip install .[bar].

However, I find that bar-script is installed in any case, expectedly telling me "Dependency missing" in the first case. According to the documentation on entry points, I would have assumed that this would not be the case, so I am wondering if this is the intended behavior. If it is, I am not sure I understand the point of being able to specify dependencies for individual entry points in the first place, if not even core ecosystem tooling like pip seems to honor them.