Capitalism is overzealously competitive in Monopoly and the real world.
Capitalism is, by nature, competitive. Monopoly is a reenactment of capitalism, in which winning is incentivized by the pride and excitement that comes with winning the game. Many people have similar feelings in the real capitalist system because wealth creates pride. The pursuit of money and repeated, incremental success is exciting. These incremental successes are the accumulation of wealth. This is exactly parallel to the game, where players buy properties one or several at time. Having established that the capitalist system and Monopoly are perfectly parallel, it is worth noting that the two systems therefore elicit the same feelings. One of the most common complaints about why Monopoly is a miserable game is that someone always steals from the bank.  This is perfectly akin to white-collar crime. Both create strife between people, be they bankers or Monopoly players. Yet another way Monopoly’s capitalist structure destroys families is that it creates situations where people’s wealth is threatened. Losing players often grow extremely, even overzealously, protective of their money. Monopoly causes familial conflict because it mirrors capitalism, which harbors conflict and competition intrinsically. In this way, it can destroy families.
Capitalism is competitive, but Monopoly is merely a board game. Despite the fact that Monopoly uses a capitalist system as its structure, it is still just a board game. Capitalism’s presence does not compound this level of competition, so Monopoly is no more competitive than other board games that do not feature capitalism. Having established that Monopoly is a mere board game, it is time to establish that board games do not destroy families. As such, Monopoly does not destroy families. Board games might sometimes create familial disagreements, but when those arise during a board game, they are no different from the disagreements that happen over who is washing the dishes. The competition and friction that arises among family members during a game of Monopoly exists throughout their daily lives, and may be amplified by a game of Monopoly. But since this tension does not exist only during games of Monopoly, it is that overarching tension that destroys families, not Monopoly itself.