In the general case, people don’t complain that <insert competitive sport or board game of choice> is boring because it always involves playing the same scenario with the same rules over and over and over.
So why do a vast number of commentators feel that a PvP game such as All Points Bulletin having a repetitive mission structure is a design flaw?
APB certainly has its flaws, but this is not one of them. Could it be improved by adding new mission content? Obviously yes, but then football could be improved if they secretly added a minefield one week, maybe changed the ball for an angry wolverine the next; it doesn’t mean that football is fundamentally flawed when the organisers choose to leave the framework the same and let the players create the content instead.