Why are they destructive?

The crying expression may change into a hateful grin. It is an expression of desperation, of utter frustration. This is an illustration of the following general fact: as soon as the expression of giving meets armor blocks, so that it cannot freely develop, it changes into destructive rage.

The pleasure sensations turn inevitably into rage impulses because the armor does not permit the development of involuntary movements.

I earnestly believe that in the rigid, chronic armoring of the human animal we have found the answer to the question of his gigantically destructive hatred and his mechanistic as as mystical thinking.

--Wilhelm Reich

Why are they destructive?

Destructiveness is the outcome of unlived life. Those individual and social conditions that make for suppression of life produce the passion for destruction that forms, so to speak, the reservoir from which the particular hostile tendencies - either against others or against oneself - are nourished.

--Erich Fromm

Why are they destructive?

My thesis is that destructiveness and cruelty are not instinctual drives, but passions rooted in the total existence of man. They are one of the ways to make sense of life.

--Erich Fromm