And the original literature is problematic. Since the 1970s, Esperanto activists have heavily emphasized that Esperanto is just a neutral interlanguage, that it aims to allow everyone to keep their native language and let language diversity flourish. But at the same time, Esperantists are so proud of people creating cultural output in Esperanto, as opposed to expressing themselves first in their native languages and only then translating that expression into Esperanto.
You are right that the literature is often not good. The problem is that as a very small community, publishing in Esperanto is either self-publishing or vanity publishing (i.e. if you have the money to pay, you can get your manuscript published, and then it gets sold by Esperanto booksellers or at congresses). There is little quality control. This isn't limited to Esperanto -- one encounters this also in natural languages whose communities of speakers are only in the thousands or low hundreds of thousands.