I think this is (as I stated earlier) similar to the gun control arguments sometimes encountered.
Is it true that untrained/careless people can damage a firearm with a Dremel? Sure it is.
It is true that a Dremel is easy to purchase without a background check and waiting period? Yes it is.
Does that mean that a careful or trained person can't use a Dremel appropriately to improve a firearm? No; it just means that dumb people can screw anything up with anything.
Larry