To begin with, let's have a look at the policy which is the motivation for all the rules and laws in the Community in The Giver: Sameness. Following a man-made disaster (we assume a nuclear war), it was determined that the factors which led to this great catastrophe were things like envy, racism, and need. The survivors decided that the only way to prevent another such cataclysm from ever happening again was to rid their society of the things which could cause inequality and therefore, unrest. Of course, human nature being what it is, people could naturally not be trusted to overcome these things themselves. Instead, anything which could possibly result in inequality of thought, deed, or outcome was removed- for example, colour. If there are no colours at all, then people can't have a preference for a particular shade of skin. And, if everyone must live in the same type of house, wear the same type of clothes, and receive the same type of benefits no matter their profession, there can be no envy. The problem is, this assumes that life can be boiled down to a mathematical equation: equal opportunity + equal variables= an equal outcome. And this simply doesn't work, because it ignores the fact that people are not created equal in ability, intelligence, or drive. Even if all other "unfair" factors are somehow eliminated, you cannot guarantee equality of outcome. We see this in The Giver; even though every possible cause of inequality has been eliminated, there are those who do not meet the expected outcomes.
The other big problem with this policy is that it favours equality over excellence, which will result in increased mediocrity. For example, there are cases where physical standards for firefighters have been lowered in order to admit more women into the profession. First, as a woman I find this insulting- I don't want a pity job. If I'm qualified, great... if not, well, don't do me any favours. Secondly, on a purely self-interested note, if I'm ever caught in a fire, I want the biggest, strongest, fastest fireman hauling my crispy carcass out of the flames, not the person who squeaked through on an affirmative action ticket. Likewise, when I'm in an airplane, I want it to have been designed and built by the most skilled and knowledgeable engineers and other professionals, not the ones who were hired based on factors other than intelligence and competence.
In The Giver, the process by which they kill the unwanted children, the elderly, and other undesirables is referred to as being "released to Elsewhere". Because no one would want to say something as crass as they were being killed by lethal injection. It would rip the obscuring cover of polite untruth and euphemism off to show the nasty, hypocritical, deadly core of their squeaky-clean society. As I noted before, if you control the language, you can control the narrative. This is why you will never, ever hear a politician say that they are pro-abortion. No one wants that soundbite floating about online. Instead you hear them coyly talking about being pro-choice, or, even better, for a woman's rights to make her own health care choices. They don't have to worry about the baby's right to choose because (see above paragraph) they've comfortably decided that it's just a fetus anyway, so who cares. As the Chief Elder says, sometimes it is necessary to maintain a facade for the good of society.