To a degree minimalism increases usability, cuts down on distractions with other links to other articles,media,etc and lets the user focus on the article or whatever work they're doing if its a desktop app.
To be quite frank I'm sick of websites with three miles of whitespace on both sides of an 80 character wide column article text and no navbar or links to get to the website's homepage.
examples (from HN's top articles about 30 mins ago) http://mkronline.com/2012/10/30/you-arent-imagining-it-the-web-is-a-mess/ http://googleblog.blogspot.com/2012/10/googles-most-advanced-voice-search-has.html http://joel.is/ I'll admit, to a degree, some of it is bad coding/design using fixed sizes in pixels instead of relative sizes for things (em) so the page renders the same independent of screen resolution.
The same sort of thing is going on with desktop applications, menus and options are getting ganked and hidden. example: http://uberwriter.wolfvollprecht.de/
Eventually if designers/developers don't get a grip on the faux minimalism fad I have a feeling the UI of the future will be a blank (white) page with a single button in the center for everything.
I really can't be the only one who feels this way.
PS: for "minimalism" done right IMO see http://gmailblog.blogspot.co.uk/ the sidebar layout is functional and fairly bare, but it still suffers the whitespace problem on the right side.