I consider myself the main responsible for this bug, so if the current patch (which I didn't look at) passes all tests, doesn't slow things up (unlikely, I would think) and also works with some more involved styling code then I'm fine with it.

These formatting functions were added to the ttk module to make it easier to create and adjust styles using Python. It wouldn't be possible without them unless the person basically coded in Tcl while in Python. These functions ended up being used in other places (as was noticed here) for convenience. All in all, I'm glad someone else is using the module, reporting, and improving it.