Because many people have not been playing the SP campaign, EA may have the mistaken impression that SP is a "lost cause" and so may not fund the Ending DLC properly -- especially since they are committed to giving it to us for free.
Basically, it comes down to this theory: Bioware looks for the sales, first and foremost. Even moreso now that they're owned by EA. But with everyone being so distressed over the single player mode's plot, with single player being so involved and multiplayer being so relaxed, all they see is how much time that people are putting into multiplayer and how little they're putting into single player. So a large group of fans are here to make a statement.
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For more information, you can check out Retake Campaign:
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