This is not totally true. It depends on what else you eat apart from the avocados.
If you eat no other source of fat in your diet, it would be that bad to eat two avocados.
However, if your diet includes more fats, such as oils, meats, nuts and dairy, two avocados would not be that good for you. If you replace all saturated fat in your daily diet with avocado can infact be very healthy for you.
2 medium avocados are about 500 calories. That is around 20-25% of your daily calorie intake. That is ok if this is the only fat you eat during the day.
So if instead of butter you spread some avocado in your bread for breakfast, instead of oil you make a dressing from avocado for your salad and you eat your lean protein with some avocado salza, it is way much more healthy than eating saturated fat alternatives!
Its generally not a good idea to eat an avocado by itself as a snack. An apple is a better choice.
You can blend an avocado and make a salad dressing without extra oil. This can be a full meal that can help you lose weight and have plenty of energy.