Under the law that the WTS likes to cite so often, df'ing corresponds to capital offenses, offenders were put to death. Based on their reasoning then, you are dead and how can you ask a dead person for money?
*** it-1 p. 787 Expelling ***
The judicial excommunication, or disfellowshipping, of delinquents from membership and association in a community or organization. With religious societies it is a principle and a right inherent in them and is analogous to the powers of capital punishment, banishment, and exclusion from membership that are exercised by political and municipal bodies.
*** it-1 pp. 549-550 Crime and Punishment ***
Major crimes under the Law. Capital crimes. Under the Law the death penalty was prescribed for (1) blasphemy (Le 24:14, 16, 23); (2) worship of any god other than Jehovah, idolatry in any form (Le 20:2; De 13:6, 10, 13-15; 17:2-7; Nu 25:1-9); (3) witchcraft, spiritism (Ex 22:18; Le 20:27); (4) false prophecy (De 13:5; 18:20); (5) Sabbath breaking (Nu 15:32-36; Ex 31:14; 35:2); (6) murder (Nu 35:30, 31); (7) adultery (Le 20:10; De 22:22); (8) woman marrying with false claim of being a virgin (De 22:21); (9) intercourse with engaged girl (De 22:23-27); (10) incest (Le 18:6-17, 29; 20:11, 12, 14); (11) sodomy (Le 18:22; 20:13); (12) bestiality (Le 18:23; 20:15, 16); (13) kidnapping (Ex 21:16; De 24:7); (14) striking or reviling a parent (Ex 21:15, 17); (15) bearing false witness, in a case where the penalty for the one testified against would be death (De 19:16-21); (16) coming near to the tabernacle if not authorized (Nu 17:13; 18:7).
In many instances the penalty named is ‘cutting off,’ usually executed by stoning. Besides this being prescribed for willful sin and abusive, disrespectful speech against Jehovah (Nu 15:30, 31), many other things are named that bear this penalty. Some of them are: failure to be circumcised (Ge 17:14; Ex 4:24); willful neglect of the Passover (Nu 9:13); neglect of Atonement Day (Le 23:29, 30); making or using the holy anointing oil for ordinary purposes (Ex 30:31-33, 38); eating blood (Le 17:10, 14); eating a sacrifice in an unclean condition (Le 7:20, 21; 22:3, 4, 9); eating leavened bread during the Festival of Unfermented Cakes (Ex 12:15, 19); offering a sacrifice in any place other than at the tabernacle (Le 17:8, 9); eating of communion offering on the third day from the day of sacrifice (Le 19:7, 8); neglect of purification (Nu 19:13-20); touching holy things illegally (Nu 4:15, 18, 20); intercourse with menstruating woman (Le 20:18); eating fat of sacrifices.—Le 7:25; see CUTTING OFF.
*** w88 4/15 p. 27 pars. 8-9 Discipline That Can Yield Peaceable Fruit ***
8 In the apostle John’s writings, we find similar counsel that emphasizes how thoroughly Christians are to avoid such ones: “Everyone that pushes ahead and does not remain in the teaching of the Christ does not have God . . . If anyone comes to you and does not bring this teaching, never receive him into your homes or say a greeting to him. For he that says a greeting [Greek, khai′ro] to him is a sharer in his wicked works.”—2 John 9-11.
9 Why is such a firm stand appropriate even today? Well, reflect on the severe cutting off mandated in God’s Law to Israel. In various serious matters, willful violators were executed. (Leviticus 20:10; Numbers 15:30, 31) When that happened, others, even relatives, could no longer speak with the dead lawbreaker. (Leviticus 19:1-4; Deuteronomy 13:1-5; 17:1-7) Though loyal Israelites back then were normal humans with emotions like ours, they knew that God is just and loving and that his Law protected their moral and spiritual cleanness. So they could accept that his arrangement to cut off wrongdoers was fundamentally a good and right thing.—Job 34:10-12.