Usually Keynsian economics is understood as economic thought that is based on aggregate demand, this is for example the view Wikipedia takes. [1] From there it is straightforward to argue that higher wages lead to higher employment, a view that makes Keynsian economics popular on the left.
The view, that too high wages cause unemployment, is a staple of supply side economics, the view that the economic process is driven by the supply side.
Krugman argues a lot about sticky wages recently, but not because this is a central tenet of Keneysian economics. Krugmann argues about sticky wages because it is a good argument against the troika's handling of the Greek crisis, since the internal adjustment in the Euro area would either mean inflation in Germany or deflation in Greece.
The view, that too high wages cause unemployment, is a staple of supply side economics, the view that the economic process is driven by the supply side.
Krugman argues a lot about sticky wages recently, but not because this is a central tenet of Keneysian economics. Krugmann argues about sticky wages because it is a good argument against the troika's handling of the Greek crisis, since the internal adjustment in the Euro area would either mean inflation in Germany or deflation in Greece.
[1] https://en.wikipedia.org/wiki/Keynesian_economics