I realize the title is pretty strident, but I'm convinced that laboratory classes are poor pedagogical tools when you consider what they exist to do and what other educational activities students can be doing with the time spent.
In a typical lab, students are pressed for time to use a technique for the first (and often last) time, as they compete for insufficient space at a sparing number of apparatus. It's very typical to hear a senior undergraduate chemistry major say something to the effect of, "I don't know how to run an NMR, my lab partner used to take care of that while I did some of the other stuff." Of course, not all schools have an NMR machine for students to learn on, and I realize that I should be thankful for my expensive 1st world and 1st class (I hope) education. But I'm not really being an ingrate, I'm just making the observation that I don't learn that much in the lab for my effort, and neither do most people.
I say this because I recently had a voltammetry lab, and I am still pretty convinced I had no idea what I did--that I learned essentially nothing. I mention this lab in particular because I think it was emblematic of a lot of lab problems: Lab instructions were vague, and students who prepared their lab notebooks in advance arrived in class to discover that the experiment had changed enough to add some time. The equipment was old and finicky, and it would have been amazing to play with, except that preparations of multiple solutions and the actual scanning process took a considerable amount of time... enough to go over the allotted lab period. Everything was done in a rush, so there was no time to understand the theory being applied.
I don't think that this kind of experience is uncommon, or for that matter, new. I remember reading Glenn Seaborg's autobiography where he writes about recreating lab experiments at home with his lab partner after hours, since it gave them the time to really understand what they were doing. I find myself trying to do the same thing, to some extent. I have a small lab setup at home, though I'm not able to conduct more advanced experiments. I also find that even when I'm pressed for time in the lab I work in as an undergraduate research assistant, it's a very different experience. Partly it's because I actually develop skills by iterative use, as opposed to merely familiarizing myself with them in a three hour blaze of panicked glory.
But here's the thing: I get it. I really do. I understand why lab classes are designed this way: It's about familiarization rather than skill development. The question I ask is whether mere familiarization is worth the time and money invested in these lab courses? There is an argument that they exist to teach scientific writing, but I think it would be far more useful to subject students to a scientific reading course. The "run before you walk" approach seems to dominate in this particular area for whatever reason, and lab reports end up being incredibly time-consuming when students have to process multiple datasets, leading to the same rush-factor I've been putting forth as a main problem. If there is anything I've regretted about my chemical education thus far, it's how much of it I sped over without really getting to look into it or wrestle with it.
That said, I understand why labs can be useful, and I don't think they're completely useless pedagogically. I'm just incredibly disappointed with them, and I think they can be a lot better. Some suggestions I have off the top of my head are to conserve time to create the challenges where the challenge can be of the most use. Making standard solutions is a valuable skill for a chemist, but at a certain level of education, it's a waste of lab time. It's more important that you spend time learning how to use an instrument that you've never seen before than in mixing solutions you learned to calculate in high school. Another suggestion is that more pedagogy should be focused on reading and perhaps even replicating literature. It took me a long time to read scientific papers because I didn't know how to read one. Eventually, I taught myself that skill. Yet I've been writing lab reports since late in elementary school. This is why I'm not sure that writing lab reports has a direct line to being able to think critically about scientific communications.
Anyway, rant over. But I encourage people to tell me what they agree and (especially) disagree with. Some of this might just be my experience, and maybe you attended an institution that did labs really well.