Scorpios are notorious for cutting ties and forgetting about the person and having absolutely no guilt or love for the person yet still if they can see that person destroyed they would happily watch/participate.
This is coming from a previously VERY negative Scorpio...though I was not mean, I was destructive towards others and myself emotionally and used to stress people out very badly. It is something all SCORPIOS tend to go through...it is impressed upon our ego and we either will have to evolve or burn everything to the ground including ourselves...Most Scorpios I know have not been able to evolve past this and have lived very painful, upsetting lives (and most of the drama comes from them)...
I like Scorpio people, even though they can really sting others. My chart has a Scorpionic undercurrents- mainly through my 8th house Mars and how it aspects my entire chart (it tightly aspects Scorpio Uranus in 2nd so watch out!) I'm also Plutonic with Pluto in the 1st hitting my chart all over the place (esp. trine Venus exact and trine Mercury)... so I do understand why Scorpios have notoriety as I've been guilty of doing what they've had bad reps for (revenge, tearing others apart, psychologically abusive, etc.)
If people treat me nicely, they can always count on me and I'll move mountains for them, and fight for them. If they betray me, it depends on how much I had previously liked them. If I deeply cared for them, I'd be gearing my energy to break them in some way. If didn't care for them to begin with, I just banish them from my life never to be remembered.
I think it depends on how others treat the Scorpio in question. Maybe I've been lucky, but I've only met Scorpios who really like me and they're willing to help me out, when I don't even ask them for anything. To that, I don't think Scorpios are destructive at all. Even if they're notorious for cutting people out cold and without mercy, I think that trait belongs more specifically to Scorpio Moon, not necessarily to Sun. And besides, I think they only do that when it's the absolute end-of-the-line-I'm-done-with-your-dumba$$-this-is-where-I-exit kind of thing. I think they're pretty realistic people in the long run.
My father is an uber Scorpio and no matter how much sh*t I got myself into, how much money I cost him in having to pay for the damages I'm responsible for, he's NOT ever cut me out of his life. He wouldn't dream of it. He said that I'm the permanent liability in his life once... when I was like 17, but he's always really optimistic about me. And my father has NEVER cut my mother out of his life...even though he was the one that brought on the divorce in the first place and he totally rages against her all the time, even though they've been divorce for ages.
My ex has Scorpio Moon which meshed with my Scorpio flavored Mars and Pluto 1st house. Towards the last 4 months of our marriage, it was really a psychological bloodbath. I was tearing him down daily and I wanted complete annihilation. He was acting really cold towards me as the initial response but as time went by, he broke down. After the decision to get a divorce was agreed upon, both he and I went to our separate corners and coldly gave each other the silent treatment... while still holding on. After he moved out... I never saw him again. It's been nearly 5 years and we have only spoken on the phone 3 times- 2 of those times were money reasons. The last time we spoke because I moved out of his "part" of the state...it was he who initiated the phone call. I was only too happy to keep up silence but deep down inside, I have an urge to rage against him and murder his soul. I have to admit that I'm still really seething mad that I didn't get completely break him, even though I did a lot of damage to him. You wouldn't think that since I'm a Gemini I would be like that... but I am. Maybe that's why Scorpios like me. Majority of my friends have Scorpio Sun or Moon, but the ones that really get me have Scorpio Mars.
The truth is, NO Scorpio would allow just anyone to get under their skin. If a Scorpio keeps you and rages against you, say mean stuff to you but strangely want to keep you nearby, that means they love you. It's like scary deep love that penetrates through the soul that would last beyond eternity type of thing. If a Scorpio pushes you completely out, then consider yourself lucky in the sense that you don't have to deal with emotional intensity anymore, but you've probably lost the one person that would go through hell and back for you.
Scorpio might be guilty of indulging in psychological murders but no, the people that are uber sensitive and destructive are Cancer. If you look up the percentage of people in jail for physical (and most violent) murders- you'd find that Cancer Sun takes the cake.