Okay, he did a lot of things wrong, but I still think Soong was kind of a dick to him. He basically deactivated his kid because of stupid scared humans and instead of helping him, he replaced him.
I think the reason Data was able to integrate with humans more effectively than Lore was that he was surrounded by a bunch of understanding humans who helped him work through any problems and misunderstandings that occurred from him being a new machine. As opposed to Lore who when he had trouble regulating his emotions and seeing humans as equals, Soong and the humans were just like "Welp, he's defective, better kill him and replace him with a better one." Failing to respect that Lore was a sentient being in the same way that the crew of the Enterprise respected Data as a sentient being.
Sorry, I'm finally finishing all of TNG for the first time so you'll have to bear with all these nerd posts.
Why don't we have a c/startrek?
He was a legit sociopath who murdered hundreds of people. They were probably scared of him because they saw those tendencies. That's especially scary for an android. Like, Data is legitimately scary too, he takes over the whole ship.
Soong made it pretty clear he wanted to fix him later. Data was supposed to be the moral one, so he could use Data's performance to figure out what went wrong with Lore later on.