OK, the manicure statement was an exaggeration. Kudos to you if you only write off business-related expenses.
I'd be curious to talk actual numbers with you and determine what you consider "just getting by". I think salaried workers can do just fine if they control their spending and plan things well. We may be slightly worse off than a business owner, but for some occupations you must work for somebody else. By owning stocks of solid companies, you essentially gain an ownership standing.
My wife is a nurse. How likely is it for her to become self-employed? I work as a product development engineer (EE/CS stuff), doing mostly low-level software. It is very possible for me to become a consultant and for a short period of time I did work on a contract basis. In my experience however, consultants in my area are hired for short periods of time and are used to fill niche roles. In other words they don't get to architect any systems, they just finish a small less interesting part of a project. That doesn't hold a lot of appeal for me.
My plan is to keep my day job, but look for cheap ways to get into things like rental properties or something that wouldn't take all of my time but will provide a passive income. At the same time I control my spending and try to do as much of the home improvement/remodeling stuff as I can myself to save $. After all, a penny saved is much more than a penny earned when you factor in taxes. Basically I try to run my household like a business.
The Carnegie book basically says the way to change people's minds is not through a direct attack on them. I brought it up because that's what you did.