Even if this character is as disruptive, dysfunctional, and disliked as you describe, there can be any number of reasons why he has not been directed to the corporate off-ramp.
For example, he might be contributing mightily to the bottom line. Perhaps, in spite of himself, he is playing a key role in the company's financial success, and the company is reluctant to touch him.
There can also be political reasons behind his tenure. He may be connected to a key customer or to other sources of power in the industry, community, or even the government. Without him, there could be a major disruption in the company's ability to continue successfully.
It is also possible that the company feels obligated to him because of his earlier successes or contributions. Perhaps he provided introductions to key customers that are still sources of great revenue.
On the sinister side, he may know something about the company that could create real problems if such knowledge saw the light of day. Or, maybe his strong ties to the company are actually family ties.
You should try to learn more about what is going on here. By understanding the company's reason for keeping him around, you can better decide if you want to stick around.
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