The idea of a clean abstraction is you can predict what a particular operation will do without knowing its internal implementation.
For higher-level languages, this is generally true for the effect of a command: you can work out what a line of Ruby does without needing to think about the underlying assembly language. There are other abstractions (aka levels/layers), such as virtual memory, the OS and the implementation of the CPU itself in terms of architecture, transistors, silicon doping. (Sometimes these abstractions are said to still be "leaky" because to understand performance issues often requires knowing the underlying implementation - that's important but distinct from just knowing what it will do.)
A common criticism of git is that the abstraction is not clean - you need to know what it actually does underneath in order to predict that a command will do. It's not just a problem of an inconsistent UI (though it is that), but that the user model that the command sets out (the abstraction) does not match up with what git will actually do.
The OP's criticism is that legit (great name BTW) doesn't address this: people will use this simpler, friendlier UI, and inexplicable and weird dangerous things will happen (e.g. data loss). C++ might blow your leg off, but git can make you never have existed.
NB: I haven't looked at legit closely enough to tell if this criticism is valid (and OP offers no support - OP, please elaborate). I'm just clarifying the issue.
For higher-level languages, this is generally true for the effect of a command: you can work out what a line of Ruby does without needing to think about the underlying assembly language. There are other abstractions (aka levels/layers), such as virtual memory, the OS and the implementation of the CPU itself in terms of architecture, transistors, silicon doping. (Sometimes these abstractions are said to still be "leaky" because to understand performance issues often requires knowing the underlying implementation - that's important but distinct from just knowing what it will do.)
A common criticism of git is that the abstraction is not clean - you need to know what it actually does underneath in order to predict that a command will do. It's not just a problem of an inconsistent UI (though it is that), but that the user model that the command sets out (the abstraction) does not match up with what git will actually do.
The OP's criticism is that legit (great name BTW) doesn't address this: people will use this simpler, friendlier UI, and inexplicable and weird dangerous things will happen (e.g. data loss). C++ might blow your leg off, but git can make you never have existed.
NB: I haven't looked at legit closely enough to tell if this criticism is valid (and OP offers no support - OP, please elaborate). I'm just clarifying the issue.