Let me explain...
A simp is just a guy or girl who is scared of outcome. Outcomes such as breakup, divorce, quarrels, fight, decision making and co.
A simp is just someone who in his or her right mind knows the answers, decisions and solutions of his or her current predicament in relationship but rather stay muted maybe cos he or she is scared of fight or breakups.
E.g a man who knows that his girl only agrees to give him sex in exchange for money or for gift even though they are in relationship can be called a simp.
Also, a girl who persistently keep aborting for a guy who she knows will not marry her even in next life is a simp.
Please, simp is not an avenue to instigate hate against women or men but an eye opener to our good men and women who will rather hurt themselves than make a decision.
When you see a simp, encourage and help him or her. They are going through hell.

The first mistake came from the fact that you don't understand that a word can be ambiguous (polysemous)

Redpillers abuse it like ibo.

Is there anything that is not abused here?

Very correct, OP. Many here do not know d meaning. Simp comes from Simpleton which means a low IQ Person.