Philosophically speaking, we live in a world where the number of spaces doesn't matter anymore (although it did matter in those pre-historic pre-Internet times). Spaces may be lost in HTML, in word processors or in an editor that accidentally wasn't tuned for Python. However neat and readable it is, just try to show your code, for example, on some minimalist web forum like this one. It's too bad you can't, isn't it?

It is also true that Python has survived already, but I doubt this concept would leak to new languages.

Upd: In other words, it's electronic typography that made the space character irrelevant.