Please, do not call people writing fine free software libraries "offenders". The "offenders" are the one who decided it was fine to phase out a more than 15 years old language without any respect for its user base. From a (professional) developer point of view, Python 3 is a new language and is treated as such. I don't think Python would have seen such adoption if developers were told up-front they would have to "migrate" all their code in ten years.