But this still misses the point about HyperCard, which was that Hypercard was its own toolchain. To get started with it, you didn't have to:
Install a separate editor Learn a separate editor Install a build system Learn how to build a project Learn how to share code Deal with dependencies
It's the no-separate-toolchain feature that made HyperCard so accessible, and which was influenced by SmallTalk.
Modern programming is a nightmare in comparison - including modern app programming.
Just because Apple uses Objective-C doesn't mean it's approaching app development in a SmallTalk-like way. Getting an app out of Xcode and into the store is a horror story of provisioning profiles, debug vs production builds, sandboxes, entitlements, and so on. Obviously people manage to fight through this, but it's a long way from being friendly and accessible.
IMO only VBA gets close to being a successful no-separate-toolchain environment - which is one of the main reasons VBA became so popular.
(You could argue Python is, but I don't think it's equivalent, because unlike VBA and HyperCard the first thing the user sees is the editor, and not a product that's obviously and immediately useful, but also happens to include a code editor.)
I think the reason people are scared of such things is not because they are incapable of learning the tools, but because developer culture has a good reason to make it look hard. Otherwise, why are we payed so well?
Note that Javascript is supported in addition to AppleScript as a user level scripting language.
Much of the Mac OS is in fact open source -- see Darwin and other projects. However having the code for the OS available -- or having XCode installed -- does nothing for user programmability.
This comment is a good example of why it doesn't work for us developers to see ourselves as typical users.