Why can't you parents just say thanks, instead of whining about education and teachers. Reminds me of the speech in A Few Good Men about complaining about the manner in which the security is provided.
I get the feeling you just don't get it. There is no money in education. It's been cut for at least 10 years, or it's be diverted into things that are not pupil centred.
Teachers give up there time for free to do these activities, less and less teachers are doing it, particularly adventure sports where the risks can be higher.
If you can't afford don't go, if you can go. Why should kids. Be prevented from going on trips because some parents would rather buy fags, vodka and Nike trainers than spend money on their kids?
It won't be long till school stop offering these trips, hopefully then you will stop moaning. Fat chance!