That's an opinion, not a fact. In fact staff cost have more than doubled over the last year, while page views are stable. You can easily see this from the KMPG report: http://upload.wikimedia.org/wikipedia/foundation/e/e3/FINAL_...
From the SCFs on Page 3 of your link, staff costs in FY2013 were $15.98M and staff costs in FY2014 were $19.98M. This is only an increase of 25%. I'll take your word on the traffic stats but your assertion that staff cost has more than doubled is easily disproven.
They're static?
http://stats.wikimedia.org/EN/TablesPageViewsMonthlyAllProje...
Sept 2014 - 23.1B views
Sept 2013 - 17.9B
Sept 2012 - 19.1B
Sept 2011 - 15.8B
Sept 2010 - 14.5B
Sept 2009 - 11.8B
Sept 2008 - 10.6B