I find that to be a bit extreme and suspect that the person you heard it from is just trying to make a buck. Believe it or not, today's cars have fewer problems than they used to because of computerization. So that can't be the issue.
As for the oil, oil manufacturers say their oil is designed to last longer than the 3,000-5,000 recommend oil change. So call me cynical if you want but I think mechanics just want your money. As for the tire rotation, it is a good idea to rotate the tires to ensure the tires wear evenly.