1. Their focus was Soros. They were criticised, and they essentially said "we haven't done anything wrong that needs to be addressed, he must have another motive for criticising us, find out if he's going to get rich from this somehow". They set out to attempt to discredit Soros, for the crime of criticising them.
2. Having failed to find a financial motive, they did discover that he was funding a FB pressure group (which you might expect of a wealthy critic). That was then used to smear the group, among the people for whom "is funded by Soros" is an effective smear.
3. Many of the people appealed to in (2) are anti-semitic. It's why the smear works. It's therefore an anti-semitic act to use Soros as a smear in this way.
In sum: they used their financial power to attack a critic of theirs with an ad hominem smear that had an anti-semitic basis. That's not the act of a laudable organisation. It's a controversial act.