I get and agree with the point you're making, and like the distinction that you're making, but I'm going to quibble a little about the choice of the name "adding happiness" as the counterpart to "fix injustices".

"Happiness" is a real stretch to describe the thing that a lot of these startups are "adding". "Pleasant distraction" might be a more apt phrase, or even just "pleasure". Or "yet one more goddamn reason to start vacantly at my smartphone, ignoring everything around me", if you're of a cynical bent.