The 1,200 calorie recommendation is based off of the standard that MyFitnessPal abides by which states that for both men and women, 1,200 calories should be the minimum number of calories consumed each day. Consuming under 1,200 consistently can be unhealthy and lead to deleterious health consequences. Users should consult their doctors for further medical and nutritional advice.
Also, please know that 1,200 is the gross calorie, not the net calorie, minimum. Regardless of how much you workout, 1,200 will be the minimum number of calories that must be consumed to qualify for a completed food log.