Does Deuteronomy 21:18-21 Condone to Abusive Parenting?

There's the criticism that the Bible commands rebellious children to death. Here's the verse that disturbs a lot of people because it sounds like it condones parental abuse:
Deuteronomy 21:18-21 
If a man have a stubborn and rebellious son, which will not obey the voice of his father, or the voice of his mother, and that, when they have chastened him, will not hearken unto them: then shall his father and his mother lay hold on him, and bring him out unto the elders of his city, and unto the gate of his place; and they shall say unto the elders of his city, This our son is stubborn and rebellious, he will not obey our voice; he is a glutton, and a drunkard. And all the men of his city shall stone him with stones, that he die: so shalt thou put evil away from among you; and all Israel shall hear, and fear.

It seems the Bible says that parents should directly kill their rebellious children for the slightest sin. But they don't realize that there's a much bigger context here. A parent can't just kill their rebellious child unless that person was a danger to society. Here's also another issue that many fail to consider. Deuteronomy 19:16-19 makes perjury punishable by death and Deuteronomy 17:6 demands that there should be at least two valid witnesses before anyone could be put to sentence. If the parents lied about their child out of a petty quarrel then the parents could be stoned.

Here's an interesting excerpt from Answers in Genesis on the same topic:
Let us take note of what abuses this particular passage actually protects people from. While providing a way to rid Israel, a theocracy from its inception, of criminal excesses, the law actually protected individuals from injustice, even legalized injustice. Moreover, the laws laid out here did not prohibit mercy.
Like ancient Rome, Israel had a patriarchal society. In such societies, the word of the father in the family was law. Thanks to this law in Deuteronomy, a father who was displeased with his son—whether justly or unjustly—could not simply kill him himself. The patriarch’s power in Israel was thus limited. Previous verses had already made it impossible to disinherit an unfavored son (Deuteronomy 21:15–17), and now these verses essentially guaranteed due process of law to protect the rights of the accused son. The trial was to be held in the city of the accused, where the trustworthiness of the parents and the son’s own character were likely to be well known. Since capital crimes required the testimony of two or three witnesses for a conviction, the word of the father would be insufficient. (According to Matthew 26:59–61, even the prosecutors at Jesus’ trial tried in vain to find trustworthy witnesses who would tell the same story!) The parents’ own responsibility in the upbringing of this defendant could be called into question, as the verses specify the son must have proven himself unresponsive to chastening.

You could think about a stubborn, rebellious, gluttonous drunkard. There's much to than just a child who throws a tantrum or a rebellious teenager. Remember the same passage that it's a pattern of stubborn, sinful behavior. You can think about the pattern of rebellion. This suggests something bigger than just answering back or a pouting teenager. Instead, the words stubborn, rebellious, gluttonous and drunkard suggest someone who is a criminal. In short, it's a command that parents should hand over anyone who's a criminal even if it's their own children. It's also a warning that parents should discipline and raise their children well or one day they may end up having to hand them over to the authorities for punishment in order to protect society from people with vile immorality. Parents were to put their own offspring to death if necessary to protect society.

Putting away these rebellious drunkards people was part of protecting people because these people are criminals. Do you remember the incident of the Golden Calf? The incident called for the end of people who rebelled. This even meant destroying rebellious children who refused to follow the will of God. David's failure as a father brought rebellious children such as Amnon and Absalom - both who should be sentenced for their crimes. Amnon's raping his sister and Absalom's taking the law into his hands were both crimes that danger the welfare of the public. Would have David raised them better he wouldn't be in a situation where he would have had to go against Absalom in battle.