In what way is it risky? I can see it being too much work for some people/companies who do mediocre work to begin with. But I can't see what risks are inherent in establishing yourself (or your company) as a thought leader in your field.
See my point about the fact that for every inbound marketing campaign there is always an equal interruption marketing plan assigned to it. Want to write blogs every week? Great! But you need to spam it through distribution channels (twitter, facebbok, email campaigns, PPC, etc)
Long-term, I think inbound marketing is way less risky for one simple reason: We're living in an age of increasing choice and increasing transparency. As buysers/consumers, we're naturally going to lean increasingly towards companies that deliver a better product/experience -- not towards those that happen to place more frequent ads. Those that build their brand by delighting customers (all the way through the process from marketing to sales to service) will find that their investments create greater returns.
But, as I said, I'm biased (but that doesn't necessarily make me wrong).