There's a recent discussion on the coreutils mailing list, where some
people complained about the default ls output with latest release. On
coreutils 8.25 ls will wrap filenames with quotes if it includes
whitespace.

And when people protest, the answers are usual arguments; it just happens
on the console output, or just add -N to your aliases etc. etc.

Here's a discussion with the response from the maintainer as well:

http://unix.stackexchange.com/questions/258679/why-is-ls-suddenly-surrounding-items-with-spaces-in-single-quotes

When this version hits the distributions, it will break many scripts. So
why change the default behaviour?
--
aldemir