The difference is that your home security system is not an artistic expression.
One of the components of my system is a computer that can literally do 90% of the functions I want, but I'm just using it as a dumb proxy.
Just because my art can do something does not mean it's not art.
At the very least, it's valid to compare them on the level of work that goes into each, compared to the benefit that each provides (in one case, a functional security system, and in the other, a piece of entertainment).
Your line is wrong.