It's not easy to go legit, especially in today's job market, depending on where you live in the world also.
The US is unique with its high salaries for tech work (on the lower end of those of high salaries is pure ops work like this though). If you're in a country where the average sysadmin salary is substantially lower (to pick on Eastern Europe for a minute, you're looking at the equivalent of ~$30-35k USD/year), it's not hard to see why its tempting to go the cybercrime route.
> to pick on Eastern Europe for a minute, you're looking at the equivalent of ~$30-35k USD/year
This is a disingenuous claim. Not only are there software engineers in rich western European countries that in absolute terms earn less than that but also your east European software engineer still earns multiple times their country's average salary.