The tool is available to use and you can use it in whatever way you want. If it works and does what you want it to then go for it but I think it’s a bit of a stretch to claim it’s just personal preference.
Arguing performance by saying that in some situations you won’t see any real difference doesn’t prove much. If you just build a cube out of BSP or out of meshes and run it on a modern PC then you probably won’t see much difference. But when you’ve built a fully polished level trying to run on last generation consoles or hardware it’s a different story and having tools available to properly scale content without rebuilding it is pretty handy.
Similarly arguing workflow because in a specific example it’s quicker to do something doesn’t really say much about the overall workflow. TheFoyer specifically said complex shapes are desired and those are almost impossible to create with BSP. So unless you have nothing but straight or angular walls, floors, windows, etc, then you’re going to spend a lot more time trying to create using BSP.
The fact that you’ve experienced a “slew of problems” is not a reflection on the method when entire games are being shipped with levels made only of modular meshes.