You are correct, someone with the capability to develop such a program would likely have more lucrative ways to use that talent. But selling such a program might just be that lucrative. Poker Edge HUD proves to me that there is a market for programs that circumvent a site's Terms and Conditions and give an unfair advantage to players willing to break them

For those who aren't familiar, Poker Edge is a program that screen scrapes as you play to get hand data, then uploads it to a shared database of all hands played by all users of the program, then downloads statistics on the players at your table based on the entire shared database of hands. This type of data mining is prohibited by every site's ToS, but as it is one of the only ways to use a HUD on Cake Poker, many of the grinders break the terms in order to use it.

Cake does now allow HUDs to be used on a per table basis, I have no idea what impact this has on the use of Poker Edge at cake.