Why few companies used "Income Statement" terminology for "Profit & Loss Acct" in their financial statements ?

This is the common Accounting Terminology which does use traditionally in many industry but as per IAS-  1 it never be suggested to use Income statement or Profit & Loss prefer to  Statement of Financial Performance. Lacking of professional knowledge and guy who is the responsible to prepare Financial Report his merits does recall to use  Income statement or Profit & Loss Account

Thanks 

Both refer to Statement of Financial Performance

As per IAS1, it is neither Income Statement nor Profit & Loss, it is " Statement of Financial Performance"

While "Income Statement" is US terminology and "Profit & Loss" is UK terminology