Hi Paul -
No you haven't missed the point. Using two filters is better... but (a) dichroic filters vary from enlarger to enlarger, so the system is rarely as accurate as I would like (b) colleges don't always display the two filter settings, only the one (and I've got too few brain cells left to waste my time memorising the settings on a system I prefer not to use) and (c) remember I'm talking about teaching to a varied range of students, some of whom begin to glaze over as soon you try to explain about these weird colour filter things are important ("what have they got to do with B&W Photography?...").
'A' Level and National Diploma students aren't always mature, self motivated, adults and they often have limited powers of concentration. But, just because they may not be the next Stephen Hawking, doesn't mean they shouldn't be able to enjoy, understand and eventually become motivated by photography? They may need to 'grow into it' more gradually with the help of supportive teaching - and supportive teaching involves smoothing technical things out for the students who aren't technically minded. (Smoothing doesn't mean ignoring - it just means leaving it until the time is right).
Some people say that you learn by making mistakes bit it isn't always true. Many students arrive in college having had bad experiences at school, where they've failed in a (British) system that's still geared to success for clever students. These 'failing' students desperately need success built into their learning because they've forgotten what it feels like - they've known nothing but failure in the past. If you give them too steep a learning curve they give up because they're used to failing, it's what they expect to do. Give them success and they're putty in your hands and, with a little effort, you can do wonders.
It's easy teaching clever students, it's the also-rans that need most work - but they can be the most rewarding.
The photo industry needs ordinary students just as much as it needs the brilliant ones. Do you want to go to a lab and have your films/prints developed by someone who enjoys their job, because they find it interesting and a challenge ; or, do you want to go to a lab that only employs students with degrees in photography but who feel the work is beneath them and boring? This is a real problem in the photo industry. We can't all be David Bailey (I'm not!) but we really need people who are well motivated at all levels.
Sorry, this has turned into a bit of a rant... But it's heart felt - I spent over ten years in 'special needs' education and my specialism was teaching design and technology to deaf students - I know a lot about how to teach people who aren't stupid but have difficulty learning (I've taught many extremely able students, too). I don't like to see teaching that decides who's stupid and not worth bothering with, before it even starts. If you understand colour filters straight away, that's cool. But, if you don't, do you want to be ignored because someone 'clever' decided that you're too stupid to bother with?
Phew!
Jerry