Earlier quoted context omitted.
The different platform argument was easy to make when it was called ".NET Core". Almost impossible to make when it's also called ".NET", quite deliberately.
No, really, version numbers within a broader brand that can indicate incompatibility are not something non-technical users with any familiarity with modern consumer society are unfamiliar with. I get that techies sometimes have preferences for perfect and eternal backward compatibility within a named product line, but trying to pass this off with “how will you explain this to non-techies”, and then treating non-techi…
Upgrade it today as I'm off to play golf."