Hmm, I somewhat doubt that avocado fats could be easily made into candles, for example. The point is, though, that since tallow is so much more easily turned into soap/candles etc. than other types of fat such as olive oil or whatever, that it is more suited for these purposes than as food.
I am afraid you are being quite ignorant, here. Sure, the higher one cooks a food, the worse the effect, but the various food-tables still show high levels of heat-created toxins for (low-)heated foods very high in saturated fats such as pasteurised butter and correspondingly much lower levels of toxins in plants cooked at the same temperature level. Since pasteurisation typically involves temperatures below boiling, it is quite clear that claiming that animal fats are hardly ever harmed except by very intense heat such as frying or grilling, is absurd nonsense. Oh dear, this reminds me of that old ridiculous argument by william that tallow could not possibly be toxic since it could not be altered at all by any heat below 300 degrees Celsius!