Most people don't actually say it out loud, but this is all directly implied by the "personal responsibility" retort that is wildly popular among people who don't actually suffer from a given malady, in response to attempts to address it collectively.
However, I dont agree with your supposition following from that.
I think that obesity is a symptom of a cultural problem worth solving, not an individual moral failing, and there are better ways to learn than death.
There are lots of things in our culture that result in physical and mental sickness. It is good to treat the symptoms, but we should also pay attention to the cause.
Culture operates both at the individual and collective level. One can not exist without the other. One can not change without changing the other. Personal beliefs and actions shape collective culture, and culture shapes personal beliefs.
It is the natural consequence of the human body's strategy for finding enough sustenance to drive that big brain over an evolutionary timeline that was mostly dominated by scarcity.
We like to call it a disease because we want to live longer. But all of the consequences happen after most humans have procreated, so there is no evolutionary pressure[0] to change it.
[0] Yes, I understand evolution isn't quite that simple