It is literally propaganda, but could you explain to me how it is bad or negative propaganda?

The overarching motifs of the show are that the Chinese state is committed to protecting the rights of the workers. Let me give you an example:

In one arc, a factory owner hires mercenaries and dresses them up as cops in order to break a strike. In response, the anti-corruption bureau gets involved and arrests said mercenaries and demands a negotiation on behalf of the workers.

Another arc is about a Chinese businessman who has been bribing corrupt party officials in order to push for a return to bourgeois rule. When his accomplices are arrested, he is 'forced' to flee to Amerika, where the only job he can land is one of manual labor - a janitor - making shit wages and experiencing great disrespect for that occupation. His Westaboo petit bourgeois son convinces him to do this, claiming that Amerika is the true land of opportunity.

Arresting corrupt party officials and punishing bourgeois criminals are good things, or do you disagree?

I will say - from my limited perspective on the machinations of the Chinese people's republic - I believe that the show is quite brutally honest. It shows privatization occuring. It shows the ramifications thereof. Sympathetic older characters yearn for the days of Mao. It shows class war in action.

Let me also ask: is it not worthwhile to merely engage with propaganda from elsewhere, even if it is negative? If you maintain critical thinking skills while watching it, I believe you can learn more about China in its entirety from this one show than damn near anything coming out of imperialist rags like HRW, the BBC, or WSJ.