I think the issue is more broad though.

While a “punishment” that involves calling oneself a loser is a problem, the entire approach of punishment-based learning has given way to reinforcement approaches because they tend to be more effective in the long term without the negative effects of punishment-based approaches.

To put this another way, using punishment to stop using social media is probably not a good approach either way. Yelling “I’m a loser” is just one of the worst variants of this specific approach.