He's flip-flopped over single payer several times just in the last few months.

Bernie has been fighting for it for decades.

Yang doesn't seem like a sincere candidate at all. His UBI seems to be merely an attempt to gut the entire social safety net. He is also opposed to minimum wage.

With Yang you'll end up with your thousand bucks a month, no other forms of social services if the thousand dollars isn't enough to live on (which it isn't especially if you have children), no minimum wage, no rent control if your landlord decides to raise your rent by a thousand dollars a month (and of course all other landlords would follow suit).

It would benefit the wealthy and leave the working class destitute, which isn't much different than what 4 more years of Trump will lead to.

Beyond policy, it is more than a little strange that the majority of "YangGang" people you see on here or on Twitter are of the Pepe avatar variety. People who, if you dig into their history, post a lot of white nationalist memes and seem to be right-wingers claiming to be "former" Trump supporters.

It's almost like Yang's (who has basically no chance of winning the nomination) support is astro-turf coming from the Republicans meant to take support from Bernie (who has a great chance of winning both the nomination and the general) in order to give the nomination to someone like Biden or Warren who has less chance of winning the general election.