I have no interest in learning how to putt all over again.
I think this is largely the crux of the issue for many people.
I guess for everyone who is used to the flash version it depends upon which type of player they are, or what techniques they have used to judge putts and some other shots. Those that have been used to using grid measurement calculations or avatar backswing clicks and other more complicated computations are going to struggle in the new version if all that is invalidated.
For myself, I have never used any of that. I use some fairly simple mental arithmetic to calculate putt strength and I give my best guess for break based on experience and 'feel', if you like. That may help explain why I'm a mediocre putter but it also means that adjusting to the new version is not such a big leap for me, and others like me.
Nobody likes feeling they have gone backwards in their ability to master the game, although rather perversely that is what initially happens when we are 'rewarded' for improving by consequently tiering up, at least in the first few tiers. So that's the way I've been treating learning about putting in the new version - as if I just tiered up to a new and unfamiliar green speed.
Many such as yourself who don't wish to relearn any game skills will quit, and I'm not criticizing you or anyone else for making that choice, although I do think it's a shame. Personally I've enjoyed the challenge of it all, but then I have no status or regular Ready Go earnings to maintain, and no technique I am especially reliant upon so perhaps it's easier for me in that regard.