`let` over `var`?

I notice in the examples const is used but in the source var is all over the place. I suppose this is one of those why-fix-it-if-it-works things, but I have to ask what was the thinking behind using the more problematic, functionally scoped var over let?

Truth be told I am convinced (and helping to convince my students) of the dangers of var in general and that its time has past. Am I missing a solid reason not to say this?

[rwxrob]

Makes sense. I was confused by the use of const (a JavaScript 2015 thing along with let) in the example code in the main readme. That implied an assumption of at least that version required in the framework.

[I have been looking for a framework written in ES6 to use because I have no desire to promote further use of any previous standard despite backward compatibility issues. I realize that is not for everyone. I was kinda hoping as new as hyperapp is that it might be one brave enough to throw off the old—especially after reading the ‘drop JSX’ thread. 😁 ]

[Swizz]

To follow backward compatibility ES6 come with most of the ES5 feature. So writing ES5 is actually writing ES6.

I mean by that you can still use var and claim you are using ES6 as let, const and var are part of the specification. They are all three a different meaning.