Ryan Walmsley has a piece suggesting you shouldn’t learn programming before going to university. It’s worth a read.
Personally, I am not against people learning to code before they get to university. I am, however, not in favour of people who have no coding skills arriving at university and starting with Scratch. Scratch is a superb tool for teaching kids how to program, and a bit about how computers work. It is not a suitable tool for adults on a coding specialist code in my view. While I am not the biggest fan of Java (disclaimer: have yet to review Lambdas in Java 8 and this may make some of my frustration go away), and I recognise that some people have issues with the lack of strong typing in Python, ultimately, once you get as far as university, you should at least start with tools you have a fighting chance of using in the income earning world. And there are a lot of them. Not in the top ten is Scratch.
Like a lot of things, tools need to be used appropriately and Scratch is an absolute winner in the sector it was designed for. But I have a book on my desk here that teaches kids how to program in Python and if kids can do that, I see no reason why we need kids level languages like Scratch at university level.