Personally, I think it is for the same reason that they have been persecuted throughout history. They were becoming too successful. And had the capability to become too powerful. Which is what seems to have happened again (or, in the case of the Roths, had already happened but they were smart enough to avoid problems). Jealously is a powerful emotion.
I’ve worked for three or four jewish owned companies. One, a jeweller, was an absolute rogue - lovable, but totally untrustworthy unless, perhaps, you were also a jew. If you were a jewish mate, no worries, if you were a jewish friend of a friend, be careful, gentiles fair game!! I had access to all his books to try to save his business - he wasn’t shy in explaining it all.
Another pair of brothers were a typical rags to riches through hard work and seizing the opportunities that presented themselves. Much more ethical (except when it came to taxes, maybe) but one thing was clear; they were always willing to help out any jewish mates that might need a hand. Good to their employees too.
Another jew was a multi-billionaire: literally rags to riches, started out buying waste rags and bagging them up for machine shops. His brother was also a multi-billionaire of his own making. Neither of them terribly happy people I don’t think, but they’d always helped each other out, and their acquaintances (the only friend one of them had was reputed to be Johnny Walker) were mostly jewish.
The common factors that I observe in all this were:
hard work
networking, especially with other jews
willingness to help other jews especially, on trust
I never regarded the first two examples as being particularly smart guys. The second lot were reasonably good at picking good e/ees. The third brothers were probably pretty smart in their time, but when I knew them were starting to wither. Definitely not sprightly 75 year olds.
But the teamwork, willingness to help, take the odd risk, trust one another; all this pays off. Hence they tend to be more successful than other groups of businessmen, whether of a racial, religious or geographical background. And if they are successful, they are usually rich, and thus influential - so people can easily be influenced to hate them.