Many things cannot be created individually, no matter how smart and creative you are. Think of pyramids, space ships, - or even GMail. It's about leveraging the resources of a big company.
And not to forget the low risk: you build something while you are on salary vs. building something for equity that may or may not worth dollars in the end.
Also apparently American-type slavery was a historical abberation. A typical slave in the past was not unlike a salaried employee today. He was well-treated, earned good money for his services and was able to free himself after accumulating enough of it, which is not unlike the FU money many a startup founder wants to have.
[0] - http://en.wikipedia.org/wiki/Egyptian_pyramid_construction_t...
If you don't think enslavement to a particular person is worse than working now, you need a reality check.
Also consider that technology sector is somewhat special in this regard. Your typical unskilled worker is pretty much a wage slave. Many a slave in the past (again, excluding US) was in much better situation than your average friendly neighbourhood supermarket clerk.
Unless you are using some exotic definition of enslavement, there is a fundamental difference between slave an employee. A slave is a property of his owner [0], thus slave has no agency and is completely dependent on her/his owner decisions. Employee may choose to be dependent on her/his employer to any extent she/he chooses, but it is her/his choice. You may argue that both slave and employer may end up being completely dependent on her/his owner/employer, but from the point of view of the law and society the situation is always completely different.
http://en.wikipedia.org/wiki/Indentured_servant http://en.wikipedia.org/wiki/Company_scrip http://en.wikipedia.org/wiki/Penal_labour [4] http://www.nytimes.com/2012/11/17/business/global/ikea-to-re... [5] http://www.reuters.com/article/2008/09/05/mexico-walmex-idUS...
Because not everybody wants to build a company.
I made my own company,in the end I become greatly successful, but it took a lot of work, my savings, risks, people around(friends and family), telling me I was crazy, that I should be working for the man because it was safe.
It is not for everybody. I have people working for me that are smarter and more creative than me, but they don't want to be leaders, or do public speaking, or go out of the lab, talk to the customer, or making risks.
If you make a company, or if you work for yourself, you need to do all those things and more in a competent way.
I can't speak for everybody, but there are plenty of things I can do at Google that I cannot do on my own. Google engineers have access to world class compute clusters, CDNs, data analysis tools, and state of the art libraries for machine learning, speech, nlp, dnn, etc. Having resources like that available empowers creative people to hack around on their big ideas.
I've certainly found myself at odds between projects I'd Love to tackle versus bills that Have to get paid. After enough failures and false starts, it becomes less personal risk and more general survival. I look forward to going out on my own again and trying some more, but I need to contribute to my current employer first as I save up the energy and resources for my next personal endeavor.