As someone who works in VFX I can sympathise with CCP on this. However the real question is: why should port everything to 3? none of the software in VFX uses it, plus a lot of people aren't really up to speed with the changes. What is the point? yes the language "purer" but that doesn't make my life easier......
The point of maintaining the source code to the latest version is to guarantee its survival to the long term: at some point you will have to pass the ownership to another, younger, dev that might not have been taught into this older technology; or port your script to a newer hardware, and eventually deal with an sub-optimal or incomplete VM. Either you maintain to the latest version and distribute the cost in time or…
See that place running COBOL? Yeah, that's your bank.