I've not found PixInsight to be user unfriendly - it is difficult, but not unfriendly, and it is difficult mostly because *I* do not understand some of the specialized tools and their applications - I am not an astrophotographer but I use many of the tools for image processing. To condemn it seems hasty and unfounded, unless of course you have used it and found it to be doomed to failure for whatever reason. If the creator of the application states that his emphasis is not on a pretty interface, but on the design and implementation of a toolset that provides flexibility and precision above and beyond what might be currently popular or available, I suppose that is a description he feels is relevant to folks looking for a similar tool. The workflow is different than Photoshop, but in a good way, providing a non-linear, object-oriented quasi-node-like environment for producing workflow solutions that can be stored, re-used, scripted and programmed. In addition, there are methods for branching your workflow with multiple paths to a result, all the while preserving the original data. Add to that tools that provide an extended ability to work with linear and high-bit data and you have an environment that is geared more toward working with raw data. The gory details are exposed to the user throughout the workflow, should you choose, so one can control the result with was much micromanagement as one sees fit.
Like any application, there is a learning curve - it is steep but manageable if you know what you are looking to do with your data. As I posted earlier, there is a website dedicated to learning resources and the documentation is extensive within the application itself. It is obviously not a tool for everyone, regardless of how great it might be and I can respect that. I'm not sure how one can argue that it is bloated, other than to characterize something that is filled with things not useful to that person as bloated - in that sense, an application like Lightroom or Photoshop is almost entirely bloat for a lot of people. For others, it is just about perfect.