Just because students are working - or even collaborating - doesn't necessarily mean they are all engaged. We have a long way to go to achieve complete engagement in the classroom, but I'm not sure that's what we want either. Not only might a fully-engaged student body be chaotic, but there is something to be said for compliance. Educators need to know the difference and the appropriate times for each.
In this world where employees are given assignments - perhaps unsavory assignments at that - and where employees are thrust into collaborative groups or assembly lines, those employees must be able to complete the assignments, often with specific parameters. There are times when conformity and compliance are the desired result - both in the work week, and in the school week.
Like every buzzword that comes swooshing through the educational pneumatic tube, even engagement must be taken with a grain of salt. While I love it conceptually, and while there is value in the spirit of entrepreneurism and fully-free engagement, it just should not be the end-all method for raising and educating our children.