I get the point, python 2 scripts aren't fully compatible with python 3. I've written a little python and know that to be the case. However, I can predict wit

I get the point, python 2 scripts aren't fully compatible with python 3. I've written a little python and know that to be the case. However, I can predict with near certaintly, if python 4 doesn't break python 3 scripts, people will complain if "python3" doesn't invoke python 4, because they've always used "python3" to run the new python and "python" to run python 2.