In my own experiences, people have mainly said they're jealous of my appearance, and a lot of the times there is immense honesty in jealousy. It's one thing to call someone beautiful but it's another to bring yourself to actually proclaim to someone that you're jealous. I don't think I could ever express personal envy for someone if I didn't mean it. There are just some points of honesty reserved for real situations, and that's one of them.
I think criticism is what leads to people's desire for appreciation. If there was never judgement or negative subjectivity, it's likely that people wouldn't have as much doubt about their passing abilities. This comes from the people who are insecure themselves as well. They may see other transgirls and be completely baffled why anyone could think they pass, and then convince themselves that they will turn out similar in the vein that they won't pass or express aesthetic femininity. That's where the desire for outside opinions comes in.
This is not just about passability. The world is full of delusion, smoke and mirrors. Countless times have I seen young men and women in tears after being told they lacked a sufficient amount of singing talent in auditioning for American Idol. It's because the people they loved and trusted had supported them in a way that would eventually do more harm than good because they went in there with too much enthusiasm, fueled by the fact their families told them they possessed talent in that particular area. I've even seen post-auditions where their parents and aunts and uncles or even the auditioners themselves are yelling at the judges and telling them that they truly do possess that talent, and it is almost exclusively due to the confidence the people around them bestowed upon them. There's no rule book. It's all subjective, and some people just can't stand the popular opinion.
That being said, it's obvious that just because someone auditioned for American Idol and didn't make it doesn't mean they should give up singing. If people are true to themselves, they will go for it anyway. What may not achieve the best results in the world or be beneficial for anyone but them is what will make them happy. Surrounding yourself with yes-people is where the problem lies. Some people seriously need to be honest with themselves and accept criticism. You don't have to look at the world as either fluffy rainbow land or the dark depths of the 9th layer of hell. It really is not that dramatic. It's not about being able to handle or trying to deny criticism. You don't always get to do that unless you hide yourself away forever and never talk to another soul that doesn't agree with everything you are, say and do. You don't escape criticism...you measure it. You find out how much you need in a way that will improve you as a person, if you are indeed looking for that improvement.
I think if people are expecting a type of criticism or lack thereof, they should state it based on their expectations and wants. If you post a picture, you can either get severe amounts of unrelenting and painful negative honesty that you may not be able to handle, or you could be lifted up into the skies by a barrage of sugar-coated and supportive complements on a silver platter covered in gold leaf and an exotic white truffle. However, if you explicitly state that you want honest but kind criticism regarding your appearance, or whether you're just seeking compliments or positive opinions on how this makeup looks on you or what clothing does and doesn't work, that's where real progress comes in without the extremes. I have confidence in the fact that I will pass with flying colors and so I post my pictures without stating what I want; I'm one of the luckier transgirls and so I doubt people are going to tell me I won't pass when nobody has questioned it for a second so far. People I know, people I've talked to very little, and people I've never met have all told me their honest opinions and I have never gotten a negative one so far. I'm as critical of other people's appearances as I am my own, and if I think about it as "If I saw this picture of another transgirl, what would be my honest, unhinged internal opinion?". Being as critical as I am, I know that I will pass. Nobody I've met has said otherwise, and so that gives me reason to believe I truly will look and feel beautiful.
Let's be honest though, some people have ridiculous standards for others' appearance. I don't believe there are many people that can't pass. Sure, you can be a 6'7" super soldier with buff abs and a hard face, but I've seen people with ridiculous amounts of muscle, size, facial and body hair that I would never assume could pass still manage to look beautiful. Not just passable, but beautiful. That's without FFS too, which is what some transwomen feel they should resort to. So even if you feel like you won't pass, there's always that chance you will, and fantastically. Others are more genetically fortunate for it or have more significant effects on their bodies resulting from HRT, but that doesn't mean people without those perks will be unable to pass. It's 33% appearance, 33% voice, and 33% personality and attitude. A friend told me yesterday that it's 50% confidence and I agree completely. So looking female and passing physically (which are what people are aiming to get opinions on in the passing thread, it seems, considering most people just post pictures and not videos showing off their voice or mannerisms) is not what it's all about. If you truly feel female, then be that way. You should have no trouble passing on the inside if you just believe in yourself.
That's my opinion.