George Soros is a euphemistic stand-in for "the international conspiracy of rich Jews" -- a persistent scapegoat with a very sordid history.
I could understand the left loathing him more - due to his involvement in the financial sector.
I have a tendency to view him positively because of his support of the concept of the Open Society and his espousal of Popper's political project. I don't know a huge amount about him beyond that but this alone makes me lean towards regarding him as a force for good - even if the idea of billionaires spending money advancing political agendas is deeply troubling on the whole.
It's important to clearly state what is meant when people talk about Soros' "liberal" or "progressive" values: the work I have seen is almost exclusively concerned with the mechanisms of politics, not the content. It is motivated by his experience of seeing both fascism and communism devastating his native country and opposes both extremes. The work I was involved in organised debating competitions for students from Afghanistan to Zimbabwe and everything in between and there's nothing "liberal" about it, unless you count allowing women to participate on equal footing as such.
Also it's worth noting that factual statements about Jews can be used in antisemite contexts. For example, "there are so many Jews in Hollywood..." is not incorrect, but it's easy to imagine how that phrase is typically used.
OTOH, unless we're saying Jews in Hollywood, or George Soros, get a free pass just because they happen to be Jewish (assuming Soros even is; I suspect most people who criticise him don't know), then we need to be careful of silencing legitimate criticism by falsely labelling it anti-Semitic.
Read what the leaders and far-right populist movements in Poland and Hungary say about Soros and you can't miss the 'old conspiracies'.
That has nothing to do with how his name is used by online posters as an antisemitic shorthand.