Because their QA team tested it with this version of Python. And their support teams are ready to assist with this version of Python.
Yes. Using Python in the first place is usually a mistake, although no one got fired by using Python, so I guess it's used because it's popular. The problem with Python that fanboys fail to accept but which in actual reality hits nearly every project is that each version of Python breaks compatibility both backwards and forwards (you might not always notice if the project is very simple and thus not using many of the features, but
something breaks every freaking time). It's not just Python2 vs. Python3, but really a moving target. You either target one
exact Python version and require user to have that exact version, or you maintain your code all day long to match the newest version, and require user to keep updating their Python to the newest release as well. Or you use something as horrible as docker to distribute your software plus the correct Python version.
PSA to all who want to develop software:
* Do not use bullcrap like Python or docker
* Avoid dynamic linking, link statically if possible, and therefore:
* Avoid library dependencies like plague;
* Only use libraries to do very complex things, like OpenGL for 3D graphics
The danger of "just using a library" to do something as simple as formatting and sending a certain packet was demonstrated on the xz backdoor disaster.