* Some companies have absolutely no in-house tech staff to speak of, and so they want to invest in technology exactly once and never have to deal with it again.
* Some companies have in-house tech people, but are entirely marketing/sales driven with little or no input from the tech staff. So they focus exclusively on writing new features and never clean up technical debt.
* Some companies choose a platform to bet the farm on, develop a huge amount of in-house code for it, and then realize that since they wrote it for specifically the exact version of the platform they first installed, any upgrade involves a complete refactor/rewrite, which they then dismiss as too expensive.
The first case can be solved somewhat by subscription-model managed services where the upgrades just happen at the discretion of whoever's managing the platform.
The other two are failures of management and planning, and absolutely should be laid to rest at the feet of the management staff involved. Preferably in an expensive way, pour encourager les autres.
What companies often learn too late is that there are basically two options:
1. Make maintenance -- both in terms of upgrading underlying software, and addressing accumulated technical debt -- a regular, required part of their process, or
2. Occasionally face a potential existential threat from the unbounded cost of staying fixed in perpetuity to a stack that "already worked" once upon a time but no longer does due to lack of upstream support and available developers to keep it limping along.
The genuine problem is that "what does this do for next quarter's results" is the only concern, which means long-term thinking is actively discouraged.
python35 will be soon be coming to EPEL also.
RHEL4 = Python 2.4 RHEL5 = Python 2.5 RHEL6 = Python 2.6 RHEL7 = Python 2.7