"Uses" people by creating products other people are willing to pay for. Just like your local pig farm "uses" the animals to provide you food you are willing to pay for.
Mega is just being a midleman here. What's so wrong about it, really? If an industry goes down because it can't compete with "free", then maybe it should go down because technology makes the business model unprofitable? Big players go down and small ones come to rule the game, it's not like people stop caring about entertainment. But of course this all whining about piracy is exactly about securing people's own position and ability to survive in the competitive market. After all, an industry-wide collapse could very well mean loss of a job(not for a single person, but also for co-workers etc) or at least huge cut in income.
In the end it's just everyone playing for themselves. Hopefully in a few decades we have machines creating superior content for us(at least to some degree), so we can finally start getting rid of the publishing/content providing industries which hinder technological progress and start to focus on consuming whatever we find most suitable for us, without legal or ethical barriers. Everyone wins if we don't let bullshit legislation hinder the progress.