Because it is not designed to. Have you read the Help files on Credit Card Processing and how it works and how to enter the settlements?

I have not.  I am new to SAGE with 6 companies.  I am trying to reconcile the bank statement and find it odd that a system would not have credit cards post to bank reconciliation module. That you would have to manually enter them there after they have been entered into AR seems like  we are doing the work twice.

If you are new to Sage 100 then your best friend is the Help files first, then your reseller and then Sage Community. The Knowledge Base on the Customer Portal is also a big help.  There are numerous videos on YouTube.