Those who impatiently & foolishly jump in with just any broker (without checking out their background and then finding out all too late that they cannot withdraw their money) and without any real understanding of the forex market, habitually traded blindly & without caution, and suffer frequent account wipe outs will say the forex is a scam....while those who have become wiser, trade cautiously & with prudence, and practice good money management will say there is money to be made from the forex market.
So, whether Forex is a scam or not is relative to which side of the fence we are at.