It isn't personal preferences. Braces are completely superior, using indentation alone causes problems:
*Mixing of the two causes programs to perform differently, but the bug isn't visible. This once cost me 3 weeks to track down a bug where one line in 30K from a contractor used a tab instead of spaces. This isn't the only time I've seen it cause bugs, just the worse.
*Copy pasting from the web is nearly impossible.
*When editing other people's code you don't know what to use. I actually just copy paste the line above every time, its the only way to assure it uses the right thing.
This stupid concept has cost more time than any other language decisions I've ever dealt with.
Now you're going to say "if you just follow the style guide...". That's not an answer. If you just wrote code the right way there'd never be a memory issue in C++ either. If you want the style guide to be necessary, make everything other than the style guide a syntax error.
Python is completely unusable just due to this issue.