WHY IT'S BAD
With SAS, the perpetrator has received the BENEFITS of a particular vice. It could consist of sleeping one's way to the top, or lying a lot, or getting divorced, or indulging a vice until it gets tiresome. At that point the perpetrator makes a big display out of quitting the vice and condemning it publicly. It's like climbing a ladder out of a ditch and then pulling the ladder up so others can't get out of the ditch; and to add insult to injury, the perpetrator ridicules the desire to use the ladder.
Like other forms of hypocrisy, it's destructive because it enforces stupid social codes. If the social codes were right all along, then the perpetrator should not get off the hook for violating them, but, in effect, he gets praise for having done so (and having "kicked the habit"). If the codes were wrong, then they should be confronted . And finally, it's bad because it creates a meritocracy of bullshit.