Did that change in a more recent version? According to the (admittedly old) source linked from the Wikipedia article, integrators are allowed to skip HDCP but incentivized with reduced royalties if they do support it.

https://web.archive.org/web/20081218170701/http://www.hdmi.o...

> For each end-user Licensed Product, fifteen cents (US$0.15) per unit sold.

> If the Adopter reasonably uses the HDMI logo on the product and promotional materials, then the rate drops to five cents (US$0.05) per unit sold.

> If the Adopter implements HDCP content protection as set forth in the HDMI Specification, then the royalty rate is further reduced by one cent (US$0.01) per unit sold, for a lowest rate of four cents (US$0.04) per unit.