I for one agree with that. It would be interesting, though, to tease apart 'stability as form of government' and 'stability as regime'. For a long time in many countries (including most of Europe) 'monarchy' was the stable form of government in one sense, but that doesn't mean things were actually stable. To quote Thomas Paine

"The most plausible plea which hath ever been offered in favor of hereditary succession is, that it preserves a nation from civil wars; and were this true, it would be weighty; whereas it is the most bare-faced falsity ever imposed upon mankind. The whole history of England disowns the fact. Thirty kings and two minors have reigned in that distracted kingdom since the conquest, in which time there has been (including the revolution) no less than eight civil wars and nineteen Rebellions. Wherefore instead of making for peace, it makes against it, and destroys the very foundation it seems to stand upon."