Of course it has limitations, sure. iPads aren’t general purpose, open systems. That’s just not in their nature. They’re still programmable though and there are many options for doing so.
Koder and Textastic are pretty comprehensive coding editors. Working Copy is the premiere git client and works well with both.
I don't believe there are any well-established general text editors that offers decent git and text editing. Syntax highlighting for a few langs, etc.
And then language runtimes. I do Elixir so I need Erlang plus Elixir. The machine could run those fine but I don't think you would be allowed to ship those via Apple's store.
Plenty of limitations. Kids can probably learn to code on them, depending on what they want and like. The argumenta may be tired but so are the unsolved unsolved problems I feel.