Been ruthless means been able to take business decisions against people or entities that are having a positive or negative effect on the bottomline of your Business.
As a matter of Fact, I am usually ruthless with middlemen. You have to add extra value, if you are not, sooner or later, whether you are a friend or acquaintance, I will boot you out. That is just my pet peeve about Middlemen in any transaction.
So you can call me ruthless that way.
Knowing when to sack or fire people without been emotional about it is also part of been ruthless,
In essence been ruthless is been what @asemota calls a dispassionate motherfucker (DMF)