The ProblemExtensions, are a very great way to add third party stuff into your Visual Studio, and your development environment, just like the Visual Studio NuGets, that provide you with great tools with just 2 clicks. This is extremely OK when you are working in a project on your own.
The real pain come when you are working on a project with a team, sharing code on a source control, or any way of files sharing. What typically happens is, someone on your team adds an extension into his Visual Studio, references the extension in a piece of code, and bom! compilation errors everywhere on everybody else's machines. So you have to ask everyone to install the right extension with the right version number that you decided to install. What makes it even worse is when you decide to install an update to the extension for some reason. This does really a huge mess, and wastes time for everybody trying to figure out what is breaking the build.
Unlike NuGets, Visual Studio has the option to automatically recover the missing NuGets when building the solution, extensions doesn't have this option, as it's not related to a project/solution but to the development environment and visual studio.