1. Because they can pay for things with it.
2, Because they don’t have to use more traditional banking methods to buy and sell goods and services with it, avoiding the various downsides of those methods. (e.g. fees, regulations, unfavorable foreign exchange rates, low local wages/opportunities, and required identification and reporting)
3. Because it’s a new thing to try out, and they like that and/or think it’s cool.
4. Because they want to do business with someone who only deals in crypto-currency.
5. Because they want to make a high-risk speculative investment (i.e. they want to gamble and/or hope for a high return on investment).
6. Because they can invest a resource they already have or estimate as low, into mining crypto with their own hardware.
7. Because they get fascinated in it and think they see likely opportunities that others may not see, and hope to profit.
As for “when theft seems to be the main way to make money” part:
8. Because they don’t want to steal money from others.
9. Because they fear repurcussions if they try to steal money from others.
10. Because they don’t think of stealing as an opportunity, for various reasons (e.g. lack of knowledge, different mindsets, not thinking they could do that and get away with it).