alt Hacker NewsThe whole push behind .Net Core was to get .Net running on Linux well and natively and was being lead largely by those of us using .Net for web. We were being murdered by other languages at the time; mono was an option but Microsoft shops usually needed to target something blessed/backed by MS.
Largely the same market (Enterprise) but not the different segment (web as opposed to Windows/WinForms).
I ported about 15 years of projects from various versions of .Net to .Net Core whilst they were developing (and sent feedback to the team - they were asking us to do that) and the process was pretty reasonable. You were only really stuck if you were using something very very Windows specific (certain image processing libraries iirc) and even then it was largely manageable.
The old full-fat framework is, AFAIK, still supported, as there's a whole lot of legacy code which is Windows specific which is still expensive / hard to port over.
Unfortunately "something windows specific" was pretty broad.
Between MSMQ, WCF over named pipes, MSDTC, and MSI installers, there's a lot to replace that is hard to provide the same guarantees or performance with straight replacements, if they even exist.
The end goal, being on modern dotnet, is better, but it's difficult to get there with a phased approach without accepting a temporary worsening, which is often hard to sell.
Especially while Framework is still supported.