I know plenty of people who are in CS for the challenge. They absolutely love writing software.

Also, nurses do what they do because they feel great helping people but in no way is that easy. Working in terminal care is extremely mentally taxing as many to all of the people they work with are preparing to/going to die. In the same way, nurses in the ER/ICU have to deal with people dying that are in no way prepared to die and that is also extremely mentally taxing. In regard to being physically taxing, much in the same way that people in CS have to deal with deadlines and long stressful working hours, nurses can often end up with up to 18-20 hour shifts with their off-hours and off-days classified as on call hours that they will usually get called in to work for.

Nurses definitely are in the field because they enjoy helping people but that in no way means that they have an easier job than people in the CS field.