Numpy supports Python 3 since version 1.5, released in August 2010. Ubuntu 12.04 and the current Debian stable carry this version. Scipy supports Python 3 since version 0.9, apparently released in 2010 as well with releases in the current Debian stable and Ubuntu 12.04.
‘Just now’ is hence a bit too late, but it is correct that many users have only been able to use Python 3 some four to five years after 2008.
I believe those versions were saddled with "experimental" wording and bugs, which made people steer away from them. This is all second-hand though, I personally never used them.
‘Just now’ is hence a bit too late, but it is correct that many users have only been able to use Python 3 some four to five years after 2008.