That had to happen because “securitized” employment led to extremely negative phenomena: absenteeism, slow down of work and productivity, the multiplication of pauses and other no-work moments in the day of labor, the increase in all sorts of vacation time, shorter holidays, and many other excuses from work.
Homo Sapiens is an animal and he can only give the maximum of him/herself, the maximum he/she is able to achieve if he/she is under pressure to do so from some kind of motivation and for many Homo Sapiens motivation has to be felt as under control, under pressure, coming from the working position (with management and other supervisors) in which the worker is.
And this securitized working class, the “securitariat,” is the main acting agent in any social upheaval in the West that has to do with income and labor regulations. In Paris in the latest upheavals against Hollande the main activists were retirees and pensioners plus a fair share of high school students and a few university students.
None of them are the precariat you are speaking of, in Europe and France at least, with pensions paid by some stable funds guaranteed by the state and high school studies being free and university studies being practically on a bargaining sales plan all the time, from free to a pittance. the UK is the only exception along that line.