You asked why vendors or freebie makers do not use your material.

I tried your matmatic floors which were perfect with my scene "retro bedroom". Anyway I think that it is not fair to take money for somebodys freebie. Moreover it looks much better then materials used on rest of my props :) I did not want create pretty floor with ugly walls and furnitures.

When you release your props with materials, it would be hard to create any furniture props which look good.