[nonameiguess]

Although this is true, there is still the additional problem that a lot of customers, specifically government customers, require frozen known versions of everything as a requirement for acceptance testing. Auditing standards for the aerospace industry require that what is running in ops is exactly the same version of everything that was running when an acceptance test was witnessed and signed.

It's a totally impractical standard for modern software development, but the developers themselves have no choice in the matter until the customers change.