Granted. Every person who ever used the Monkey's Paw to win the lottery hits the jackpot. The payout, split between an improbably high number of simultaneous winners, is a paltry $100 after taxes. Nice, but certainly not the windfall they wanted.
Everyone who uses the Monkey's Paw to wish for love has the object of their desire fall madly in love with them... Even the people that happen to be the objects of desire for multiple people. Relationship troubles caused by conflicting feelings skyrocket. On the whole, nothing really changes.
And of course, everyone who wished for mass extinction, global destruction or any other form of annihilation on a planetary scale has their wish granted, too. We all die.