Obsolete was a wrong word to use, I admit that. But from an integrator's perspective supporting both versions is a mess. The problem is that the interpreter has the same name (python), the libraries export the same symbols (well, same names, different signatures for extra fun) etc.

Like you said, Python team sees the 3.x series as the successor AND as a replacement for Python 2.x. They were never meant to exist one beside the other (or, there was no thought put into this before the release).

From my perspective, giving people the choice between 2 or 3 will only give us problems down the road, which is why I vehemently discourage it.