There’s a risk involved in talking people down or acts of depreciation in general. If you speak negative about a certain person you’ll likely generate feelings of guilt towards that person, although the strength of these feelings depends on whether one believes that person deserves it or not. If there’s no intention of reconciliation, upon confronting the depreciated person, your guilty conscience likely sparks a defensive reaction in response to your anticipation of retaliation from that depreciated person. Rephrased, whether consciously or unconsciously, you expect punishment from that person as a means of revenge since you depreciated that person.
As such, as a self-protective measure, your ego will tend to strengthen, or brace, itself so as to be able to meet any potential retribution coming from that person. As it is obsessed with the pursuit of selfish and nearsighted interests, your ego unfortunately is a selfish and incompetent defender and therefore does not qualify to be the most rational and just defender. In fact, the relationship between you and the depreciated person is likely to deteriorate if your defensiveness is, in return, met with a reciprocating defensiveness coming from the depreciated person.
With respect to oneself, the moral of the story is simple: since depreciation leads to strengthening of the unhealthy and primitive ego, care needs to be taken to limit acts of depreciation to a minimum if not avoid them altogether.
Another but related way to look at the malpractice of depreciation is this. Talking a person down is equivalent to effectively talking yourself up, relative to that person. In other words, depreciation effectively is self-exaltation; a sinful fruit of pride… one that Lucifer indulged in like no other:
2How art thou fallen from heaven, O Lucifer, son of the morning!
how art thou cut down to the ground, which didst weaken the nations!
13For thou hast said in thine heart, I will ascend into heaven,
I will exalt my throne above the stars of God:
I will sit also upon the mount of the congregation, in the sides of the north:
14I will ascend above the heights of the clouds;
I will be like the most High. Isaiah 14:12-15
I think it is fair to say that Lucifer may be regarded as the epitome of depreciation. By depreciating the whole of humanity he has acquired a colossal guilty conscience towards us and therefore enormously boosted his defensive ego to anticipate our retribution. For sake of argument I assume he has a conscience on the basis that he has has free will because without a conscience the drive to do good may be entirely absent from the start and Lucifer used to be God’s prime angel before his fall.
Scripture also discourages talking people down. Take for instance, the biblical imperative of:
“Do to others whatever you would like them to do to you.” Matthew 7:12
Contrastingly, appreciation of fellow human beings promotes a reciprocation of appreciation by fellow human beings. Consequently, appreciation promotes social bonding while depreciation seeks to achieve the opposite, ego mediated and ego strengthening social alienation and division.