Being overweight, or more extremely, obese, does have long term implications for your health, yourability to do some activities.
Just like smoking, or alcohol consumption, or drug taking (including prescription drugs in some cases).
In my opinion, the issue stems from people who are truly happy with how they look and how they feel about themselves, versus, promoting healthy lifestyles to , mainly, young people.
There is a balance to be had... Those who truly struggle to lose weight for whatever reason, shouldn't be ostracised and made fun of... But the message of the advantages of a healthy lifestyle shouldn't be underplayed either, just in case someone takes offence.
We don't worry about stating 'smoking kills' or 'drink wisely', but somehow stating 'Eat healthily within your recommended daily calory allowance' is seen as 'fat bashing'.
Obesity DOES kill...regardless of the reason for it, and regardless of whether the person's is happy with themselves. It isn't a lifestyle that should be promoted.