Many do so describe it. That's because they are selling it and know that many people won't buy it if described as a runner. So either they lie, or use some equivocation such as "mainly of clumping habit in British conditions".

The e-book isn't a bad thing to get for free from a seller, though clearly infomercial, and with the annoying incompletenesses, and collections of not-quite-useful information to pad it out. I notice at the start of the book the first "bamboo" they mention is "heavenly bamboo", which isn't bamboo at all. Also obviously aimed at the US market, as it mentions all sorts of stuff you can't grow here, and rips off a lot of info from the American Bamboo Society website.