IMO this problem isn't a problem. It's only a problem with people who don't understand the game, oversimplifying what it is. TerraFirmaCraft will forever be bound by the inherent limitations in Minecraft, and since Minecraft almost never evolves under the hood, TFC will forever be hamstrung and marred with Minecraft's deep engine flaws. The game can't even keep up with other versions of itself - Minecraft for Windows 10 runs substantially faster at drastically higher draw distances and implements all the same features.
When I heard about Vintage Story, I bought it almost instantly because I knew the implications of a standalone game based roughly on TFC, made in C#, with mod support (many people forget, Minecraft to this day doesn't actually support mods - all mods require interim jar hacks/injections, like Forge or Bukkit, a mess that splinters the player base). It runs better, it looks better, it plays better, and it's gotten more attention to detail in less than a year than Minecraft still has in a decade.
I also need to emphasize that the marketing push was positive, despite the negative "it's a clone" responses - I bought the game because of it, I then convinced a friend to buy it, and I may have convinced yet another person to be buying it soon. As a programmer, I recognize good, well thought out game design, and I want to make sure it's rewarded so it doesn't go away. I'll do a lot to make sure this game doesn't go away - it's way too promising.