I think you are going in on the wrong foot here. Distinction between petty bourgeousie and bourgeoisie is not relevant here. The commenter is saying landlords being leeches is why small business owners are skimping on paying good wages (which in turn causes the “labour shortage”). This is fundamentally wrong because it is based on false assumptions. Supposing a small bussiness owner is given possession of their rented land, there is no guarantee that the money they save will be used to pay better wages. In reality the guarantee you can guarantee the opposite. They will pocket the difference because that is how the logic of capitalism functions. They will just pay the market wages for the labour anyway.

The talk of which classes will or should be antagonised and which won’t be is detached from the topic.