I have to wonder why simple english wikibooks is so small compared to en.wb. There are many potential factors:
- No advertising. People simply don't know that there is a simple-language alternative to the regular english wb. I know that our project doesnt advertise for it, and it's hard to find anybody on meta or in the foundation really pushing for simple english to become more widely adopted.
- Direct competition. en.wb already contains books for many audiences: books for children (in the form of Wikijunior), books for school students, etc. Some of our books even specify that they will be written in a particular english dialect, such as british english or "e-prime". Each book is empowered to have a local "manual of style" to help keep all it's pages synchronized, and many books take the effort to specify what language and vocabulary is going to be used.
- Less versatility. Editors on simple english wikibooks can write books in simple english. On en.wb, authors can write simple and they can write complex. We can write books for children and university graduate students without having to log in to a different server. Of course, once SUL happens this will be much less of an issue. Readers, also, have the benefit of being able to progress from simple books to harder books without having to switch projects.
I do believe that the two projects should be merged. Not because simple.wb has failed in any way, but because they would benefit from our environment with more readers, more writers, more infrastructure, and a closer proximity to other efforts such as Wikijunior. It makes good sense to me, and I hope that other people seriously think about it.