There are a large variety of reasons why a person would be obese, whether it be they have some type of disorder that makes it difficult to lose weight or they're just a lazy little fuck.
If they're lazy, then I completely agree with calling them out. There are so many resources available to people to lose weight that it is not necessarily easy to live a healthier lifestyle, but the path to becoming healthier is very clear and obvious.
There is a much grayer area if this is a disorder. Many obese people became obese because of some type of trauma, or they have some type of medical disorder where it is difficult to not gain weight, like leptin resistance. For the trauma part, many people have for example been abused as children or abused by a spouse, and eating is a very common way that these people deal with this trauma. These are much more difficult to deal with, and it is incredibly unfair to namecall these people because of their weight because it's largely out of their control. Someone with leptin resistance literally doesn't stop feeling hungry, and abuse victims need a long and difficult recovery process to not only get that PTSD of their abuse out of them, but also to develop a healthy relationship with food.
TLDR
Being fat for no reason is bad, being fat for a reason is fine and reasonable and these people often are trying to not be fat anyway