Its not just the appalling dangers of water and electricity in close proximity but water on the floor indicates high humidity along with the heat causing premature failures in all the equipment. I guess those costs aren't a factor, however, when you're paying your workers pennies a day.
I'm 100% sure their workers aren't getting paid pennies per day. Why say something that's just patently untrue?
Premature failure isn't much of an issue when miners become obsolete in months. Very few miners are profitable to run after just 2 years, usually less.