I know some waitresses that get a lot of $$$ in tips. It is only a con if they don't actually do this. Same for the other claims made.
The poor wages combined with tax free tips will help them a lot. Thats no con.
The Californian 'solution' of much higher minimum wages just saw hundreds of restaurant chains close down instead. A dumb solution turning towns into ghost towns.
Of course, Trumps policies have downsides - don't mind the deficit, debt and coming inflation.... but these were already in place anyway.