Bamboo also has its issues [0]. I think mainly because it is kept in shape by bad stuff. Could be that your straws are really 100% bamboo, but some products are something like ground bamboo in some polymer.
The ones I have are just drilled out bamboo sticks (they vary in size and have visible bamboo structure), not reconstituted. I've never seen other types of bamboo straws (everything appears to be paper around here, once I had a pasta-straw), so I'm really curious.