To me, it's not unlike someone who uses heroin. You have a very large sect of the population that not only has never tried heroin, but couldn't ever imagine any situation in which they would try it themselves. They don't have any frame of reference to what it's like to be a heroin user, and they probably never will.
Then you have the people that maybe do it once every few years at a party or something. These are the people that 'feel fat' and 'need to lose 5 lbs'. They think they have a reference point, and maybe they have some inkling idea of what it feels like, but for the most part they're just like the other group.
Now you have the people who have used consistently at some point in their lives. They still have a decent job, and they've never stolen anything, and it doesn't wreck them if they go a few weeks or months without getting a fix. A lot of the time people around them notice it, but it doesn't truly affect them so they mostly leave it alone. Even though they aren't getting bullied or anything, there is still that ever-present internal struggle that they have with it. Sometimes they do well for a while, and sometimes not-so-much.
Next you have the people who've gone off the deep end but are trying to get their lives back. I would guess most of the folks here fall into one of these two groups. Either you're tired of being overweight and yoyoing, or you are trying to come back from being obese. These folks know what it's like to be in that pit. Many were there for years, and more are just starting to make the effort of climbing out. Most people who are down there really want to make it out and get clean, but that crap is a ton of work. A lot of people will fail and slide back into old ways.
Then you have your never-get-betters. These are your junkies. These are the people that for the VAST majority of them will live every single day for the rest of their lives without ever being close to what is considered a healthy weight. These are both the people who have given up and the people who wear fatness as a badge of honor. These are your people who say, "let me live my life the way I choose and just because I'm 150 lbs overweight doesn't mean I'm not healthy." Sure, just because you're 150 lbs overweight doesn't mean you're not healthy, but at some point I promise you that you will encounter weight related health issues. It's like a 20 year old saying they have strong lungs even though they smoke a pack a day.
Either way, if you're a junkie you have one of three options. You can do nothing about it and have some people pity you and some people make fun of you, but consistently not get the respect that you otherwise would if you were a healthy person, you could try and change the world around and hope that some day people will respect you regardless of whether you help yourself, or you could actually try. Almost no one looks down on someone who is actively trying to better themselves, and from my experience the negativity comes from people who don't want you to make them look bad because they don't want to address their issues. Contrary to that, there are places like this sub where you get nothing but uplifting comments from other users as long as you're willing to try. HAES is to me like someone saying that you shouldn't judge me for not trying to fix my issues. I know it's hard. I've been there. At least put in the effort and stop crying because some people don't like that about you.