SAP and other ERP's are made lot more difficult by different Tcodes that made decisions difficult, agreed?

The previous program is capable of solving facilities easily answered cost,

I don't agree with this as T.Codes are an extra facility. You can perform any task by two different ways1. By following the menu path2. Using the short cut i.e. T.Code

So T.Codes are an additional facility provided.

I use SAP but SD department that have mainly IT professionals some times made moduless that may differ in different reports, for example customer over due reporting is different in one report than another.