Sabariel wrote...
Because Hawke knows things Elthina does not 
And everybody else knows things Hawke doesn't so that really isn't saying much.
You can't invoke "the hero is always right" when the hero is played for a dupe for 90% of the game.
Again, she is not required to run from Kirkwall completely. She can still do Grand Clericy things from a safehouse (maybe... a place in Darktown... Anders' Clinic maybe? *shot*)
Now Chantry followers are wondering why she has to do this, causing unrest and maybe panic.
Hell, forget that. Now the Divine gets word that the Grand Cleric is having to hide for fear of imminent attack. The Chantry is in danger, Kirkwall is lost. Time for an Exalted March!
Blowing up Meredith would have accomplished nothing but Meredith's death. The Chantry created the crappy templar/mage "relationship". The Chantry needed someone to set its arse on fire... not literally... but Anders did it anyway...
You're right, why deal with the matter directly when you can do it in the way that will guarantee the most death and destruction possible!
Justice, everybody!