Sadly because celebrities are using these drugs I can forsee many people who are only a bit overweight taking this when just eating better and working out would be so much better for them.
People that are 'only a little bit overweight' are usually in that state because they can't control their eating via the neocortex. You can't simply say "eat a little better"; you have to modify food drive. The signaling pathway this drug targets is the one that feed into food drive.
If it’s determined to be safe (statistically), why not? Might only be necessary until we can inexpensively synthesize miR-1: https://news.ycombinator.com/item?id=34196488
However, that's a big if. Behavior modification is hard. There are both physiological and emotional factors that need to be addressed, and cause many attempts at weight loss to fail.
The drugs are a second line treatment when behavior modification fails.
(And that said, exercise is still important. Overweight or not, it has a massive impact on longevity, physical health, and mental health.)