Why don't official English sites translate the OP/ED? Many (maybe even all) series on Crunchyroll (perhaps Hulu as well) for example have no subtitles for the opening and ending.

Why is this?
This was stated by the Support Manager??(or is that just a forum title) of Crunchyroll:


  This involves getting the rights to the songs that are used as opening
  and endings for each show on the site.
  
  So not only when licensing new simulcasts would we be going after the
  show but also the opening and ending songs.
  
  A lot of bands are reluctant to let their songs be licensed as this
  means that the translation presented is -THE- official translation of
  the song.


Source: http://www.crunchyroll.com/forumtopic-803435/so-crunchyroll-why-not-sub-op-and-ed-songs-as-well

He also backs that up at: http://www.crunchyroll.com/forumtopic-758633/are-cr-subs-lacking-a-bit

So he does seem to be a staff from Crunchyroll.