Yeah, this has come up a couple times before, good to remind people!
Apparently it is possible to process bamboo with physical rather than chemical means, but of course this is more expensive so very very little of it is processed that way.
Then of course there's the fact that most bamboo (far as I know anyway) is imported from overseas (hence lots of pollution in the transport). And probably from countries with sketchy (at best) environmental & human rights records (so what does the factory look like kwim?). And even if used 'raw' as a wood, bamboo is a laminate made with lots of glues, what's in those glues??? And although it may grow very fast and without the use of pesticides, it's a very invasive plant, invading many other types of forests. Plus, as it gets more popular, more and more farmers are growing it as a cash crop instead of food for their community, chopping down native forests to make room for it etc...
Definetly not as 'green' as some media have made it out to be... I've researched and thought about this quite a bit actually. We're building a home this spring and at first I wanted bamboo floors, bamboo cabinets etc etc.. Then I realized that basically if it seems to good to be true, it probably is.
Now, that's not to say that bamboo is bad. All these issues don't negate the fact that it's an amazingly sustainable plant. And it's traditional alternatives like cotton and hardwoods aren't exactly perfect. For example cotton is a very intensive crop, relying heavily on pesticides (unless organic of course) and that needs tons of water. Many of these issues can be, and hopefully will be, addressed. But we just need to consider *all* aspects of a new product before just jumping in with both feet.