Developers are developers, that's it. They could be good or bad, but there is one pretty common thing. Significant part of them are really bad in marketing. In JED there are many (and I mean many) extensions with the description of this one. Come on JED team, do not allow such entries. How anyone could understand what this extension is about? Can you?
Joomla! Translations
We aim to provide translations for Joomla! to as many languages as possible. We also offer translations of extensions. Direct Downloads
We offer only direct downloads. We will collect the files and keep it here for you. No redirects. Installable files
Every language file downloaded from our web site can be installed with the Joomla! installer. That's it - just two clicks. 
Today I noticed two extensions in JED listed as GPL. These were also listed as commercial (which is fine), however after checking the developers web sites, I noticed that the information there conflicts with the main principles of GPL. While other bloggers may not disclose the extensions and the developers, I will do it. I will do it as it is not correct to lie your customers.
One of the issues related with the Joomla! extensions is their upgrade. Languages do not differ from the components, modules, templates or plugins. Now, if you look at the translations marked as accredited by Joomla! you will note that there is no standard of the packages (i.e. some offer all-in-one package, others not), but there is something that is missing for sure. Joomla! 1.5 offers one thing named installation method. This installation method in fact guides Joomla! that the extension is already installed and the idea of the current installation process is to replace the existing files. In the past it was common to have as a second row (after defining the document being XML) it was pretty common to have:
