Probably what led to these occurring in the first place without much questioning things the same way people are made to question something like pirating Minecraft in some form is the very adjacent communities to BotB that do these things frequently with no issue. Several users here overlap with and/or came from SMWCentral (myself included), where making SMW hacks is... well, the whole point, but there was a commonality of being forum-based websites with a good repository of chiptune and presence of chiptune musicians. So since there were enough common users, that probably sparked an interest in showcasing what they do with smw outside of just the music, and since SMWC had no repercussions for it there was little to worry about. In contrast, there's not a clear overlap between the minecraft community and BotB that might spur some form of spill-over, and what is being proposed through the medium isn't really much to distinguish it for what complications it provides. With SMW it is clearly distinct in it's identity as a format where you're making an smw hack in some form, whereas with minecraft block art, you're just using Minecraft as an advanced medium to create pixel art. Don't get me wrong, I think it's cool, but it's not far enough removed from normal pixel art to warrant a format that requires going that far out of your way to participate in it even disregarding any legal workarounds needed, in my opinion.
Basically, SMW had a precedent to exist due to community overlap, uniqueness, and relative confidence in the safety of permitting it, whereas this would be a more risky gambit or require further abstraction for a format that does little to capitalize on the uniqueness of the tool needed to create the art piece. It would be fun to see someone submit a picture of their minecraft block art build to some visual format in some way, though.
