This is not a situation of taking people who would otherwise do their 'adventure travel' on their own (in non-commodified fashion) - rather it is simply about bringing new people into the outdoor world, people who otherwise would have gone to Disneyland for their vacation.
As someone who has spent many years sailing and rock climbing, I can attest that there is a gulf between the folks who 'do it on their own' and those who require a professional, packaged tour. I find it highly unlikely that the sort of folks who would be willing to learn and experiment on their own will suddenly not do so just because a commodified experience is suddenly available to them. To the contrary.
So if commodification helps people experience the outdoors who normally wouldn't or couldn't (and perhaps turns them into environmentalists, or at least nature-lovers in the process) then why is that a bad thing?