Many forces shaping employment options are considerably larger than any one individual's choices about their own career, so I think it's fair (and important) to look at systemic trends, and what effect they have. Of course, in the short term, each person also has to make their own decisions with the systemic factors as they currently exist, so I don't entirely disagree.
I agree with you that there are many forces that shape options, but my original point was that temp work is an option. My original reply was to someone that threw out a blanket statement that all temp work was bad in the long term. Surely there are some temp workers that can benefit in the long term from the skills that they will learn and the additional income.
