Does WordPress Break the `PRE` Element?

As we all know, the HTML <pre> tag means preformatted text, and is used to do things like preserve the white-spaces in preformatted text, so that if I use spaces to align some text like this:

0
 1
  2
   3
    4
     5
      6

it will look like that, instead of letting HTML do it’s thing to collapse it and making it look like this:

0 1 2 3 4 5 6

or this

0
1
2
3
4
5
6

So why does WordPress strip out concurrent spaces before even sending code to the browser, even inside a <pre> tag? When I view the source and look at my <pre> element, the white spaces aren’t there, WordPress has entirely removed them. HTML never has a chance to preformat it, the spaces are gone. This defeats the purpose of <pre> altogether. Yet I’ve seen people using the <pre> tag on WordPress sites and their spaces show up fine. Is this something recently broken in 3.5.1??