I don't own LTA, so maybe that is a very special case. Can't speak to it.
In addition to fire hazard, tube life (both good points), my gear consumes over 100w when idle. I listen probably 2 hours a day, maximum, on average. This probably doesn't mean much, given the other factors, but at my electricity rates, the difference in energy use is $105 vs. $9. For decent tubes, that's the cost of about 2 tubes per year in energy savings. Over a few years, it would add up.