What is the advantage of Methadone over other opiates for treating drug addiction?

Methadone is just as dangerous, just as addictive and is MUCH harder to get off of (withdrawal is much worse). I've experienced this first hand. For non IV addicts who remain on methadone for years, why not just let them have their opiate of choice? Is this just politics?

: http://alcoholdrugstreatment.info/what-is-the-advantage-of-methadone-over-other-opiates-for-treating-drug-addiction