They actually went and did it.

Perhaps the number and value of the coins inserted also forms part of the password.

Claypool didn't get to spend any time teaching Samaritan a code of ethics, though. Greer threw the switch and let it off the leash; in contrast, we saw several flashbacks of Finch dealing with the Machine's early attempts at world domination.

"It seems at odds with its root as Arthur Claypool's creation and his goals for it."
Don't forget that the first 40-odd iterations of the Machine were also at odds with Finch's goals for it. Claypool didn't have the same opportunity with Samaritan.