Whenever I run a P&L report - the default offering is "this year". I always have to change it to "this accounting period".
I would guess that "accounting periods" are more commonly used than calendar years.
- of course, you may have some better-informed analytics on this
So the system-wide default could be "this accounting period".
- or alternatively, in the customisation section of this report (and maybe others reports too) to select a default reporting period.