Something being regulated does not mean that it can't be used industrially. Many types of explosives are regulated even though they are used industrially every day in quarries and mines.
Still, restricting thermite would be silly and ineffective. As a chem-lab assistant, I made the stuff in highschool. Aluminum powder is widely available and rather cheap, as is iron oxide (obviously ;). I also made cupric oxide thermite, but that didn't work as well.
