If Wikipedia were the only website I'd agree, but I don't find it useful for Wikipedia to have stubs that are simple copies of other freely available sources (especially more authoritative ones), without
some kind of synthesis or value-add. In the case of species, for example, I think there is little value in a Wikipedia stub that is just a reformatted copy of the ITIS entry (
http://www.itis.gov/). If that's what I wanted, I'd just go to ITIS. When I see a Wikipedia result in a Google search result I typically expect it to be the basic taxonomic information one would find in ITIS
plus something more. Otherwise it feels like some of that autogenerated SEO-style spam, which Google should penalize.
It also doesn't always really help in jumpstarting future improvements, if the structure doesn't align with the granularity that makes sense for an encyclopedia article. For example if there is a genus with three species, each of which is very similar and has very little distinctive written about it, the normal organization would be to write one article on the genus, with a short discussion of each subspecies in the main article, not broken out into three separate duplicative and near-empty articles. You'd only break out into separate articles on each species if there's enough to write about them that covering them as a group becomes unwieldy (this varies widely by species). If I were to hazard a prediction, it's that the English Wikipedia will as a result tend towards better organized species coverage than the Swedish Wikipedia, which will never get around to reorganizing these articles.