It may also have to do with the fact that overcoming addiction is not limited to just stopping the addictive substance.
Recovery leads to self examination and rigorous self-honesty. This eventually leads to an increase in self esteem and self confidence.
On a sub conscious level, co-workers may dislike the change because now the former addict is viewed more as competition rather than someone they can look down upon.
They used to be able to regard the addict with a certain amount of disdain and think to themselves “well, at least I’m better than that screwup. I’m not an addict. ”
But when the addicts begins to get their shit together, which in itself demands a certain measure of respect, the entire dynamic of the previous relationship is now turned on its ear. Some people find this disorienting and uncomfortable and prefer the old way where they were clearly the superior one.
This is even more pronounced with close family members who were in a symbiotic enabling type of relationship to one degree or another.
That’s one of the main reasons that people new in recovery are encouraged to frequently attend support meetings. They usually aren’t getting much support from those who were comfortable relating to them as an addict but now have difficulty relating to them as an equal. It’s an interesting dynamic.