High school lab classes - are they obsolete?

Are high school lab classes still relevant or necessary any more? Or are they an obsolete approach from a bygone era?

Many have argued that science practical classes are formulaic and lack challenge and interest for learners. The argument is that such classes should give opportunities for students to undertake experimental design, and analyse and interpret data - in short, to practice science as it is practiced in the real world.

In principle these are good ideas - blurring the distinction between the classroom and the real-world by moving deeper into the ways a community of practice actually operates. The problem is, as so often, one of time. How can learners be expected to design an experiment, for example, if they have yet to have hands-on experience of basic lab techniques? How can they identify potential areas of error if they simply have not encountered these situations before?

I would argue that there is a place for both relatively structured practical classes, and for open-ended, investigative classes - they do not have to be mutually exclusive, or have one approach ditched in favour of the other. 

In practice, the emphasis of a lab class would vary depending on which skills are being highlighted. For example, an experiment investigating the effect of temperature on enzyme activity is relatively simple to design, and learners could be expected to do a reasonable job of it. However, I see it more as an opportunity to practice a wider range of skills, including not just taking and recording measurements, but also data analysis, interpretation, and error identification. Groups could compare their own results with the rest of the class, and gain an appreciation of the importance of pooling larger datasets for greater accuracy. These are exactly the skills advocated by those who suggest lab classes are formulaic. Once these basic skills are in place, then learners would be ready to take on a more in-depth, open-ended inquiry of their own. 

We cannot expect learners to come as ready-formed junior scientists in the making. It is still the role of science teachers to guide learners, whilst providing opportunities for more exploration and open-ended investigation once they have mastered the basics. 

I'd love to hear others' opinions on this...