I sense that both TE and El both have valid points.
While engine fires and/or evacuations may be rare to an individual they are not uncommon and occur on almost a daily basis in our industry, thus the reason for the training.
The impact on the aircraft is generally ho-hum, but the impact on a passenger should they be commanded down a chute is not. Most of us would dread the experience as a high probability of injury even if it does save our lives.