HR used to have an expression for the type of senior manager organisations wanted to recruit they referred to “ A safe pair of hands”.
This was an experience individual, calm under pressure, who could be trusted to get the job done without causing controversy or conflict. Obviously such an individual favoured the status quo, minor improvements and efficiencies nothing too radical which might upset people and nothing which might cause negative publicity or embarrassed the organisation. Such a person is of little use to an organisation that is set on transformation one where the agenda is change and radical change at that.
It is quiet conceivable that you get some way down the transformation road before the board has a failure of confidence or you succumb to internal power plays. Either you brought changes in too quickly and up set people or too slowly and disappoint people. May be your methods were effective but distasteful. Maybe the organisation just was not ready to fully embrace your ideas. Maybe you alienated too many people with your unwillingness to compromise or the progress you were making exposed the short comings of others. So you had to go.
It’s not such a disaster and certainly not a disgraced to get the sack. Provided it wasn’t for accessing porn on your work lap top, making a racists joke at the office Christmas do or placing large contracts with your mates without going out to tender.
It’s a myth that being forced out of one authority/ organisation you won’t be welcome in another. In my view if you have never been asked to leave you probably haven’t been trying hard enough.
The reasons they wanted you in the first place may be the reasons they don’t want you now. I am thinking of the criticism that you are opinionated, abrasive and intolerant of those less able and less committed. These characteristics were not seen as a problem when examining your track record and your employers claim to be ambitious. Maybe you weren’t such a good fit for their set up but as you have shown before given the right structure and support you can make even the most unlikely underdogs champions.