Because `make time` and all the related Makefile targets use the local built Python in the cpython parent directory. In order to install it, one would have to go through various steps, like installing openssl, configuring python with ssl support, building and installing python, creating a venv etc. Since it's more time-consuming that just running `make time` and since it's only needed for something that in most cases is not the most important thing, I think we can just go ahead and make it optional.

Is there a downside to this change I'm missing?