When he was younger, he wanted to be respected. After everything that had happened with Luke Skywalker, after getting on Snoke's side he only wanted to be seen as something more than a kid with powers. He was angry all the time, and he took it out on everyone around him. And where did that get him?
Soon after joining the First Order, people were disgusted by him. They hated him because of who he was, of what he was. They hated him for what he could do, for how easily he could hurt pretty much everyone he wanted. He was nothing more than a kid, and nobody wanted to have anything to do with him.
Still, he didn't have people's respect. Time passed, and one person kept growing more and more insubordinate: Hux. Snoke was giving him so much control that he was probably starting to think of himself as Kylo's equal, even though he clearly wasn't. And Kylo couldn't stand the fact that Hux felt free to insult him, disrespecting him so openly, in front of everyone. That was the reason why he concentrated even more on undermining Hux in any way he could. Because Hux had the respect of everyone, that was the only thing Kylo didn't seem to be able to obtain.
Bothering Hux could make him feel a little better, but after a while it started getting old and unsatisfying. Kylo was so concentrated on making Hux pay for whatever he thought that the other had done to him, that he didn't even notice how his behavior was affecting everyone else. Maybe Hux was too brave or too stupid to be afraid of him, but everyone else was terrified. His rage outbursts, the ease with which he killed everyone who stood in his way, scared pretty much everyone else around him.
Every time that Kylo Ren walked down one of the hallways of his ship, people found an excuse to get out of his way. They probably would have scattered, running away in fear, if only they'd had the possibility to do it. But now, after everything that happened in his life, Kylo Ren was the Supreme Leader of the First Order, he was the one who gave the orders, and running away from him sure wasn't part of any order he'd ever given. Stormtroopers, however, quivered when he approached, trying to stay still on their shaky legs. They were all terrified of him, and anyone could tell. Kylo Ren's eyes were lit with pride when yet another trooper tried to change direction after meeting him. Everyone was too afraid to even cross Kylo's path.
Maybe he never got to have the respect of the people in the First Order, but he had their fear. And after becoming the Supreme Leader, without Snoke telling him not to hurt Hux, he was able to make even that stupid General fear him. Finally, everyone was under his command. Sure, everyone still hated him, but they were also afraid of him, and that was what mattered. He didn't care about people's respect anymore, having their fear was more than enough, even if that meant that everyone hated him.