@Jeff: For background, I teach 1-2 classes at community colleges or state universities a semester as a sideline to my main work, and greatly enjoy the teaching almost all the time. My wife is a tenured professor at a state U with 13 years of experience.
What rings true in Schlosser's piece is the existential anxiety of many adjunct professors who teach this way for a living. They are very well-educated, often have student loans, and are paid little with little job security. (In some institutions, lecturers do have 3- to 5-year contracts, but in others one is hired on a semester-by-semester basis.) Many lecturers have to teach 6+ sections at a variety of institutions to eke out a rung at the very bottom of the insecure middle class. (A depressing feature of life as a community-college lecturer is that I get an email from the admin every April about how to apply for unemployment benefits for the summer months.)
Schlosser is correct that bad student evals matter and that in many fields the market for adjuncts is saturated. The biggest problem, however, is not fear of being bounced by student grievance, it is the extent to which one is hostage to the larger economy. For instance, our CC department enrollments were down drastically this past semester, presumably because the overall entry-level job market in our area had picked up. Fewer students = fewer sections. There is also a problematic race to the bottom in terms of workload. "Easy" professors get more students, and also have less grading to do -- a virtuous circle, of sorts.
I disagree with Schlosser on a number of points, though. In my teaching, I routinely deal with difficult topics (human origins, origins of religions, comparative flood narratives, the Holocaust, early US experiences of Native Americans and African Americans, slavery) and have never gotten a student complaint, formal or otherwise. My wife says the same thing. In fact, these difficult topics generally have the best discussions. Our classrooms are incredibly diverse in terms of faith, background, class, ethnicity, you name it. The key, at least in history, is to let the past speak as much as possible. Give the students enough background to understand primary sources, and then let the student interact with the text. (I do also say about 50 times in discussion, "We're all clear that the owner of the slave ship is saying this, not me, right?") Also, in any humanities/social science field, we make the move from judgment ("That's racist!") to origins and significance -- What are the roots of this understanding of race? What purpose does this racism serve, for whom? How does it color other developments? As we provide tools to deal with uncomfortable texts, students gain power to channel their discomfort into meaning-making, and this tends to pay off.
The biggest disagreement I have with Schlosser is his belief that the basic issue is a "liberal" one. The problem with college teaching does not exist at one particular point of the political spectrum. Many students privilege emotional response over reasoned argument, but this is largely because they have not been taught the joy of reasoned argument. Show students how one respects and critically reads a source at the same time, and they are excited about the possibilities.
Can one have a rewarding career in academics? Yes. However, it really is a crap-shoot getting a stable, tenure track job. You have to be the very best, and there have to be schools looking for your particular specialty. You must be prepared to move almost anywhere, which is very hard on families, or make sacrifices to stay together. You absolutely must be organized and good at long-term planning and multitasking.
If you can keep your day job, though, I highly recommend teaching a class on the side as I do. It is fun to watch the light-bulbs go off in students' eyes, and fun to read Noah and Utnapishtim together and discuss the tradeoffs between polytheism and monotheism. Best!