Don't forget that if there is a lot of modules just for XML, this means that they are not covering all that the users needs. A developer won't spend it's time to build a module just to say that it has his module, specially for XML that is not a simple thing to handle. Also means that the main XML modules that are there are not simple and easy to use as the users want. Since XML was created to make the integration between different systems/programs and architectures easy. And if the use of this is not easy, is just crap. Each developer, of each XML module is just tring to find a better way to do things.