Yes, there is, because Microsoft naming sucks, and making the distiction between .NET Core and .NET Framework is the only way to actually explain modern .NET to most folks without background on .NET.
Additionally the mistake to rename .NET Core as .NET is the main reason many people still think .NET is Windows only.
Well they did have a valid reason for a rename, .NET 5.0's announcement coincided with discontinuing Mono and Xamarin, and uniting the non-Windows .NET flavors under a single platform. They also planned to iterate more rapidly and add APIs beyond .NET Standard.
But yes, choosing ".NET" as the new name was a bad idea, since now when someone says .NET you have no idea if they are referring to the modern runtime, or its various generations collectively.
I, for one, think dropping the "Core" suffix (absolutely dumb naming) was the right thing. Yes, it might have created some confusion with the old .NET aka .NET Framework but I hope it's temporary. It's been five years of .NET-no-suffix and nine of it being cross-platform. At some point people should just educate themselves and stop thinking that .NET is somehow Windows only.
Good luck with that, the .NET team keeps referring this is a recurring problem trying to get new users that rather pick something else for their startups or teaching curriculum, just go listen to .NET podcasts where well known figures got interviewed.
Additionally the mistake to rename .NET Core as .NET is the main reason many people still think .NET is Windows only.