It is tremendously detrimental when a deprecated technology has all the inertia, because it is a dead end thanks to the Python bosses refusing to move it forward. Every new package for 2.7 (and no this is not old gold - this is a brand new library for access to Bloomberg's massive and uber-valuable database), every new package that invites more people into a dead end, encourages those people to look much wider (beyond Python) when needing to upgrade. Python 3 may be growing in absolute terms, but in relative terms it's a absolute dog compared with its competitors, including Python 2. Python 3 in its current form is doing everybody a huge disservice.
I see what you mean now on old is gold and yes I agree. Corporations love old proven tech for all the obvious reasons. Not officially deprecated but that's just semantics. The underlying point is that the Python leaders are trying to turn a superhighway into a dead end, and force a long and winding detour for most people onto another highway which is only marginally better. Being forced to take that detour simply encourages the exploration of other alternatives as well. By the way if they really had balls, they would've killed Python 2.7 in 18 months. Not 5 years. Force the choice. Clearly they themselves are not confident enough in 3.