I use FreeCAD on a very regular basis and can understand why it's not more popular: it's very powerful but has some very sharp edges that will often have me using it in a state of near rage. Topological naming comes to mind but there are other various issues that I've hit like a brick wall (in that you can't work around the bugs/limitations so much as you must rework your design to avoid them which can be tedious and frustrating) when designing something non-trivial.

That said, each release continues to improve it just has further to go than most open source projects.