Alright, I will bite.
I do my own fretwork. I've bought a number of used basses that have required the frets to be levelled, re-crowned and then polished. I don't mind doing this work, in fact I enjoy doing it! I especially enjoy doing it considering the ridiculous amount of money I wasted as a teenager getting the frets on my instruments 'stoned' (might just be a UK term). I had a Strat worked on, and the "luthier" basically leveled the frets until they were flat on the top, and then never re-crowned them. He might have polished them, but I ended up with a guitar with wide, flat frets. He also decided that I needed a floating trem! I'm glad that I can do my own work, but I wouldn't want to be doing it every month, every week etc.
Frets made of anything softer than the metals commonly used, in conjunction with roundwound strings, will wear down quickly. They will also wear down unevenly. You might find that the bottom 5 frets wear out quickly. You may also find that they don't even need to wear that much before you have issues.
How do you level and crown rubber frets? Say you have to replace the first five frets after four hours of playing, frets six to ten after the next four, etc. How do you accommodate for this? You have to be able to remove these frets endlessly, then install new ones. Do you then level them as well or hope that they just all mash into their slots correctly and somehow wind up being level?
Softer frets will also compress when you fret a note, so you would need to compensate to some degree. For example if I fret the 3rd fret, the tops of all the frets may be level, but the soft material will basically allow the string to sink in slightly, and suddenly it is fretting out on the 4th fret. Do you start with a highter fret in the 1st position and a lowest fret in the 21st position, and somehow ramp through the fret heights between them? Do you simply jack the action?
