It's especially insufficient to generalize the working of the entire system from an example of a market in which employees currently have enough power to not really have to worry about the prospect of physical harm because it would be disadvantageous to the employers to cause it. Even if we take the current state of the SaaS startup market as reliable (which it isn't) the original argument was not limited to SaaS startup employees, and in other industries (including ones that are a bit down the pyramid from the SaaS companies) things are a lot less rosy for employees.