Recommened Calorie Intake

I am trying to understand the crossfit calorie prescriptions (from http://ift.tt/1nWs6d9)

The CrossFit dietary prescription is as follows:
Protein should be lean and varied and account for about 30% of your total caloric load.
Carbohydrates should be predominantly low-glycemic and account for about 40% of your total caloric load.
Fat should be predominantly monounsaturated and account for about 30% of your total caloric load.
Calories should be set at between .7 and 1.0 grams of protein per pound of lean body mass depending on your activity level. The .7 figure is for moderate daily workout loads and the 1.0 figure is for the hardcore athlete.

Suppose your weight is 60 kg your total calorie intake would be between

0.7*2*60*4/0.3 = 1120
and

1.0*2*60*4/0.3 = 1600

which seems to be very low. (The factor 2 in the calculation is because of the kg to pound conversion, the factor 4 because of the protein to calorie conversion and the /0.3 because calories from protein should be 30 percent of your total caloric intake).

Another point I don't understand is, that this doesn't distinguish between men and women.

Please don't tell me that counting the calories is not so important. I just want to understand the crossfit nutrition prescription and why the caloric intake is so low.

For me this seems to be like a restrictive diet prescription to loose fat and not for a crossfit athlete which wants to build or just maintain muscle mass and body weight.

I just compared it with: http://ift.tt/1cNIkPS which gives me above 2000 calories for an active female or 2300 for an active man (using Mifflin- St Jeor. research model).

So my questions are:

- Did I the calculations right?
- Why are the caloric prescriptions so low?
- How to explain the difference to the linked calculator?
- Is this meant for fat loss or for maintaining?

Recommened Calorie Intake