I Am Interested In The Interesting

1.) The short and final answer is nobody fucking knows, it's essentially bound up with the question, "Why is anything happening at all?"

We have such exhaustive information about how electromagnetism operates, how photons are emitted and absorbed, how different substances tend to respond to it, etc., that we've been running our whole civilization for a while now on the assumption that our understanding of all of that is accurate, and we seldom encounter any serious problems in doing so. There is so much to learn in that regard that it's easy to overlook the fact that we haven't the slightest clue why anything should act according to these patterns in the first place. Nowadays professional physicists tend to irreverently banish these sorts of concerns when they're noticed with the old dictum, "Shut up and calculate!"

2.) I'd guess the main reason is that most of us have the good sense to avoid things that are obviously spewing out way more energy than we could absorb with any reasonable expectations of survival.