The word "unfashionable" seems a bit ill-defined here. The article itself makes the argument that hydro is popular and many places either have adopted it or are

The word "unfashionable" seems a bit ill-defined here. The article itself makes the argument that hydro is popular and many places either have adopted it or are adopting it, so obviously that's not what "unfashionable" means. It seems like the core complaint here is that some people have criticisms of excessive damming, and it has caused governments to weigh the potential impacts of hydro projects before going ahead — but surely that is a good thing. Overall, I just don't really get the issue this article is trying to call attention to.