Abusive (blasphemos) means slanderous; cutting; impious.
Cutting people down or diminishing their contribution in any way takes its toll on the spiritual climate. The whole purpose of the Good News of Christ (or GODLINESS referred to in the 2 Timothy 3 passage) is to create a climate where people can thrive, grow, and develop. When people are cut down, torn apart, or criticized behind their back, there is a full reduction in spiritual power.
The same reduction of spiritual power occurs when people are NOT valued. When you are not actively affirming and giving people value, you are in effect “devaluing” them.
Cutting people down/devaluing them flows many different ways from making fun of others, mocking others, or making others feel small in any way.