For years it has been said that it is easier to find a job when you have a job. This bit of wisdom was based on two principles 1) while working and looking for a job you do not have the financial pressure that being unemployed job seekers have and 2) employed people are more attractive to hiring authorities than someone who is out of a job.
Today the world has flipped upside down. Anyone who has been with a company for a real long time is looked at having limited experience (only knowing one way to do things) and anyone who has changed jobs frequently is looked at having broad experience. Think about how companies groom executives; they do so by moving them around the organization. You should consider grooming your own executive, you, by moving around to gain broader experience.