Aside from tolerance for Antisemitism, being soft on Russia, picking and choosing on human rights (e.g. Syria), and appealing to base instincts on immigration (Eastern Europeans are keeping your wages down), what's so bad about Corbyn-led Labour?
Antisemitism:
mainstream Labour isn't antisemitic, that was largely a point pushed in our right media to discredit them. The left wing of the party is definitely anti-Israel though, and pro-Israel forces always try to conflate the two. The Labour party is much, much less racist than the Tory party on average, it's the sort of thing that's hard to prove with a neat fact you just have to spend time in a pub with either side or read a lot of their literature for dog-whistles.
soft on Russia: who knows, it's not like we have the military clout for it to matter much
picking and choosing on human rights: doesn't everyone
immigration racism - no, Corbyn's message (that i also disagree with actually) is to redirect the focus onto exploitative employers. It's his talking point on immigration along with NHS staffing, every time. The labour party has gotten worse on this but they're still miles behind the Tories
Sorry to do politics on HN but this post needed to be called out, none of these points are a combination of relevant and applying more to Labour than the Tories.
It doesn't matter how left-wing a politician appears to be, or even how left-wing they are in general; if they hold an odious reactionary opinion, they can be called out on that opinion.