Regarding the Army only highlighting the good life one can gain from joining the Army and tending not to show the negative side. What other organisation, business etc. show their true picture? One has only to watch the commercials that are blasted out 24/7 from that box in the corner to realise this.
If you are trying to sell an item, a lifestyle or anything else for that matter, you don't usually make a point of showing the negative side. Why should the Armed Forces be any different? As in any career choice the final decision is left to the individual.