I'm in the middle of pursuing an official diagnosis, and my reason is I'm too good at masking, so people don't always necessarily realise there's anything different about me, or they just think I'm aloof, nervous, fussy or morally inflexible and obsessed with following rules to the letter. But I can make eye contact (takes a little effort, feels weirdly emotionally intimate with strangers, but I can do it), make small talk, I understand and can use sarcasm and metaphors, I can make myself presentable, and many of my "special interests" are things people would consider "classy", like yeah, I can actually regurgitate a huge amount of information about Warhammer 40k, which people find weird coming from a 35 year old woman in a nice smart-casual dress, but I can also infodump about Shakespeare or History, which people don't find weird.
Once in a blue moon, I'll get overstimulated and people get really unsettled as a normally very calm, polite, soft spoken person just SNAPS and goes on a tirade or busts out crying. It happens rarely enough that it really shocks people when it happens. The worst one is people thinking I'm blanking them because they don't realise I can't always process voices over background noise, so they might call to me and I won't hear them.
So yeah, I actually totally understand how you feel about some people on the spectrum. I don't like people who use it as an excuse to act like a spoiled brat or draw attention to themselves, or who talk like every autistic person is a widdle baby who needs to be allowed to be disruptive and to never be criticised . I don't live with my parents, I have a fiance, I have a job. I keep clean and dress appropriately for what I'm doing, I try to make small talk and I apologise if I find out I was accidentally rude to people.
Sometimes I struggle when I'm overwhelmed, but overall, I'm a pretty functional adult woman, and if I'm able to rest my brain now and then and keep my life organised using reminders and schedules, I can act so neurotypical a lot of people wouldn't even know that I could summarise the entire plot of Homestuck from memory. 
I want the diagnosis but not because I view my brain's different structure as a "disability"; on the contrary, I find there are a number of advantages. I'm a fast, highly efficient, focused worker with skills in logical reasoning and creative problem solving that my employers value. If somebody needs to find a file, I know where it is, or I'll know what key words to search to find it. If somebody needs a funny joke about a really esoteric, specialist subject, they come to me. I don't care about office politics, I only care about doing a good job, because doing good work and interesting things stimulates my brain, while small talk and staring at people's eyeballs doesn't.
So why get the diagnosis? Because it is really hard to explain sometimes that the lights are really giving you a headache or you want to spend your lunch hour on your own not talking to people (I've been talking to people all morning! Give me a moment's peace to recharge! Please!) not because you hate them but because you don't want to snap at them, or that you won't remember anything a person just said unless it's written down, or the fun day in the office where there's music on isn't fun, it's actually a bit too loud and hard to concentrate, and having a piece of paper that says "Yo, I'm autistic, please give me a little understanding, I sometimes work in a way that seems kooky, but I can be a really productive and fun person if you give me a shot." can be super helpful.
Give me some tinted glasses for the lights, a nice quiet place to spend lunch, don't ask me to do morally questionable things, let me write everything down or send written notes and let me wear my headphones and I'm the model worker; punctual, polite, productive, creative, good public speaker with a brain like an encyclopaedia, but have multiple people talking to me at once, make me juggle tasks, ask me to do things that might hurt vulnerable people or break laws or regulations, expect me to wear high heels and mascara and spend all my lunchtimes making smalltalk and I'll be snappy or morose, demotivated, spaced out, inefficient, pedantic and I'll get paralysed trying to decide which tasks to do or forget a bunch of them.