Don't think I get what point you are making Michael. What mark did I miss? I thought you mostly asked some questions?

1. Why should I be arguing that optional braces are bad? I don't actually think they are. And if they were then the problem is solved by making them mandatory.

2. I don't know what point you are trying to make about Go. It solves the same problem as Python significant-whitespace is supposed to solve by using mandatory braces.

3. Sure there are lots of way of solving copy-paste. But the reality is that Python is over 20 years old, and most Python REPL environment are still incapable of handling it. Sure... maybe in the magical future it will happen, but we are not there yet. So it is is a real problem.

4. In most Julia editors you got match on braces but not on end. But why should you? You don't get that in Python either, as there is no start and end keyword to match in Python. Most editors automatically indent based on your use of end.

If you want your code to be forced to be more readable you could just have a mandatory formatter just like gofmt. I don't think whitespace has to be part of the syntax to make a language readable.

Anyway in my over two decades as a developer I have never found it to be a problem that people don't indent code blocks. Readability is usually affected by entirely different things. I think Python is here solving a non-issue.

But I don't particularly care about it, just like I don't care that much about non-mandatory braces. In fact I think the benefits of non-mandatory braces exceedes the downsides in practice.