i don't agree on bitcoin mining being a bad way to earn bitcoin, it depend
if you have free electricity or at least very cheap, you can do it without thinking, you will have a very high chance to roi, without doing the trick of selling your miners after 3 months
with that trick you can actually take big profit and in a short time, if you invest big
The fact is, the difficulty is insanely high and not all of us live in areas where electricity comes cheap. But, if you got plenty of cash in you, go to China, create a farm and see your sweet miners generating good income for you.