Would you take your young children on a cruise?

I have been on a few cruises and I have seen lots of little kids (under 10 years old) running around the ship. Some people take their babies and toddlers…... I dont understand it, I know its their right to take their kids anywhere they please, but as a parent of 2 year old, I would be way too nervous to take my son on a cruise ship. What do you think?