Update: As of Patch 5.0.5, Blizzard has corrected the issue causing the bug this addon was designed to fix. As such, I have now marked Let Me Accept! as obsolete like several of my other addons that Blizzard has made useless.
With the recent 5.0.4 patch, certain quests disable the "Accept" button on the quest frame, preventing you from picking up new quests. There are work arounds, such as relogging, reloading the UI, or typing /run QuestFrameAcceptButton:Enable(), but wouldn't it be nice to not have to do any of those?
Let Me Accept! enables the Accept button each time the quest frame is shown, so it will always be available to be pressed.