Ugh...I wrote two paragraphs but my phone died -_- I'll try again, *sigh*
I think they should but only in their free time, not as a class, unless they want a degree related to that language or something like that.
Although I am a native speaker and I'm taking the french a level, I have gone from a 0 in writing and grammar in french to an a level standard. I'm finding the A level incredibly useful and interesting, and it made me a lot more confident in the language and have the ability to discuss more complex things like the current world issues. I still had to prepare, research and plan two cultural topics and prepare myself for the exams. I didn't just walk in expecting to do well. I do agree that the grade boundaries are ridiculously high and that examiners should take them into consideration. I only achieved a C last year in the written paper (probably cos of my poor writing skills in the last question) - I got 73 out of 110 but that was only a C o.O
I think us native speakers do have to put in as much effort but we do have a headstart (in terms of understanding etc). I know a guy who grew up in spain a good number of years but only got a D in speaking. I, who grew up here but have a french background did a fair amount of preparation and of reading (with the knowledge I picked up from the past papers) got an A in speaking, which was also due to my confidence.
I will be taking the spanish a level next year, but to be honest, I think the spanish grammar is a lot easier than french, so I think it may also depend on the language.