Result Cache and simple queries

I don't really want to beat the dead horse here, however, I came through an interesting observation today.

It turned out that the latest version of APEX (3.1.2, or maybe some oldest versions as well, don't have these to check out) does use result_cache hint for a queries like this:

SELECT /*+ result_cache */ MESSAGE_TEXT
 FROM WWV_FLOW_MESSAGES$
 WHERE SECURITY_GROUP_ID = 10
  AND MESSAGE_LANGUAGE = :B2
  AND NAME = UPPER(:B1 )

SELECT /*+ result_cache */ NLS_LANGUAGE, NLS_TERRITORY, NLS_SORT, NLS_WINDOWS_CHARSET
 FROM WWV_FLOW_LANGUAGES
 WHERE LANG_ID_UPPER = UPPER(:B1 )

Both of these queries are simple lookups...