It's a fair point. But I think that the issue is that we then are lumping all of these companies into one category and we should look into what they are doing. So if we think that "dating apps" or "photo apps" derive less social value then we would tax them more than startups that derive "more value" (say, fighting disease or providing solar power). There are systems already in place for this type of incentive, where government provides tax breaks in fields deemed "socially more valuable."