This can't be true of the indented-syntax, which has two downsides:
* It's a huge barrier to entry for anyone new to the framework when they already know CSS.
* It makes porting and/or incorporating existing CSS unnecessarily complex.
(The same things could be said about HAML, but people generally have no problem writing HTML, while CSS is still a fluid and ever-changing system).
The indented-syntax is way nicer to look at, but it's a good thing that it's heading off into the sunset.
I’m also not so sure that this parser can only handle one of the two SASS syntaxes — what gives you that impression?
However, since .sass is no longer the primary syntax (nor default for Rails), and it's not supported by any new development efforts, it's safe to say that it is not the favored child.