Taking advantage of people in weaker positions of power, from being rude to a waiter to abusing a disabled person. They all make me dislike the person immediately and will likely cut them out of my life as soon as possible.
Blasting music/videos on their shitty phone speaker in public. If you really don't have headphones, at least turn it down or hold the speaker closer to your ear so you're not just annoying everyone in a 10-meter radius.
"It's just a prank bro"-people. I already hate it when someone finds it hilarious to hurt others, but if those same "pranksters" then also act all indignant and percieve themselves as victims of prejudice when other people do NOT find their "pranks" funny, they can GTFO.
There's the obvious "if you're a homophobe, transphobe, racist, abelist" etc etc etc. Like obviously that makes me lose respect for people.
But I think if you judge someone for doing something that you deem "weird". I used to so that until I learned that like, hey we're all fucking weird. Who cares.
Leaving carts outside the corrals at the store. Failing to signal. Actually a lot of car or car adjacent behaviors. All of which go back to "my immediate convenience is more important than being a conscientious member of the society I live in with other people."
Some people just seem to work, then come home and watch whatever is shown to them on TV or scroll through their phone. And that's it, other than socialising, that's their lives.
People who abuse animals, beyond normalised speciesism. Like kicking dogs or cats. Or wearing fur. Or... OK normalised speciesism also makes me lose respect to someone when they know about it and they don't care.
More in general, I have some respect for people who overtly are just selfish (at least they're open about it) whilst having none for people who, acting with the same selfishness as the former, try and pass themselves as nice.
As it happens, nowadays I pretty good at reading people when I do care enough to pay attention.
If they are, in a completely literal sense, impossible to predict.
I have reached a point of no return (no return of respect) with a high ranking person recently who started out as friends with me. I had a lot of controversy surrounding me, but she promised she knew none of the hearsay was true. Then she cut me out, and it took me a moment to learn why. Then some months later she reached a point where she restarted her feelings for people and eliminated her grudges. We were friends for a while, and all seemed fine, but then same exact thing happened, she promised nothing was going to happen before she cut me out again. Again, it took me a while to learn why. I would leave that general area, but we would find each other elsewhere one day, and she seemed fine with me. All seemed well. Then I went to ask her a question and discovered she cut me out again. At this point, another friend of mine got involved, not giving her a good time (I tried stopping him, but every time I did, it would still be deemed my fault that was happening), and then she declared a truce and asked if I would accept. I consented on the condition everyone knew about the truce and that it wasn't just a privately negotiated thing. She accepted, and I have proof of the truce, and to celebrate the truce, I was introduced to her inner circle. However, I was removed from her inner circle twice, once quickly the first time and once after asking to come back in a few months later, with another few months where I wasn't removed. She then came to me and said "sorry, I removed you because I have people in my group who don't like you, no hard feelings" and I was basically like "alright, I understand". Half a month later I went to ask another question only to learn I was ghosted again. And this, combined with another person coming to me saying they bore proof she was talking about me behind my back (the prime condition of the "truce" was to not do that), I had had it. I ended the truce and lost any respect for them, and I'm not afraid to show it.
I've actually had many, many, many encounters similar to this, and so have some people I know; once in a while people who become on good terms with me again cite things like "mental illness" and "shutting [person's self] down trying to cope from being overwhelmed". I don't care if you have a delusion disorder, if you're going to see other human beings as so insignificant in your seemingly solipsist mind as to think people with different ways of perceiving a situation can understand a part of your experience they don't necessarily have any reason to think exists, that is simply reckless and you're just a jerk. Many of these people also often say "well if you would just read the room you would know what the reasoning is" but unspoken words spell out differently for everyone because it's like looking at a mirage in the distance. The "writing on the wall" is a myth, in the end it refers to jibberish because at least language is communicated.
Taking advantage of kind people.
By all means you don't need to turn down kindness, even if you're joking to make light of your need to ask for kindness that's fine but if you take their kindness as expectation, it really hurts. My mother was always willing to help those in need and people would always use her like it was their right until she broke down. I'm currently trying to convince my senior to include me in more of his meetings because he seems to be in a similar position and I'm ready to help him say no
People who travel in sweat pants and hoodies or "athlileasure" (sp?) cloths on airplanes. Yeah, I get that you want to pretend it's a big sleepover, but I don't want to be in a sleepover with you. I'm probably not looking forward to this trip and am already stressed. I just find it to be somehow disrespectful of others, not sure why.
I'm probably the weird one on this peeve, but I have to travel a lot for work. People do this shit on long distance trains too.
Other pet peeve is when someone corrects someone else's pronunciation of a word in a condescending manner. The person mispronouncing the word probably read it in a book and has just never heard it pronounced in the wild. Making fun of someone trying expand their vocabulary is just petty. There are nice ways to correct them and actually help them they could have used.