mepal
imagine if he wanted to do Tshuvah he would have to return the money and ask mechilah from every person he stole from! impossible. Teshuva requires one to rectify the situation and gain mechilah from the wronged parties, crying out to Hashem in repentace is not enough (though it helps)
thats the same situation for a baal loshon harah
which is why it is said a baal loshon haroh will probably not have a cheilek in Olom Haboh.
not too humorous