Hello,
As Stephan already mentioned to include this feature SAP has to develop entirely new web apps for every Transaction , BOR objects that can be used in transaction launcher which involves lot of investments to rethink and redesign the complex SAP GUI business logics. Of course not worth it since there are lot of other areas where SAP needs to focus to take lead in the market. 
Nevertheless, SAP has also provided option to integrate custom BSP applications and other htm pages through transaction launcher where customer can use this feature to meet his needs.