Landlords like the idea of incorporating rent payments into credit scores, since it adds extra incentive to pay on time. Or, phrased differently, extra punishment for failing to pay on time.
Framing the current default as a help to the rentier class is just silly.
The rentier class are indeed a major cause of stagnation and inequality in our economy, but they are innocent of this one.
The current default is that missing a rent payment can harm your credit score, but paying on time will never improve it.
https://www.experian.com/blogs/ask-experian/can-late-rent-pa...
This benefits the landlords for the reasons you outlined, and tenants must interact with the credit industry through additional (often predatory) means in order to build a credit history that may allow them to buy their own home. Further, landlords have an incentive against providing this positive feedback, as doing so makes it more likely that tenants would exit a relationship that is profitable to the landlord.