These machines send a bad message to kids and they are a scam. When you pay money to play a game, you expect it to work in a fair way. It shouldn't matter whether or not yo get lucky and use the machine at the right time. The game should be fair.
Most machines that are used for gambling don't make themselves appear to be skill-based. I forget where I read it, but some of these claw machines can be rigged to never pay out.
Either way, the machines should fall under gambling regulations the same way that slot machines are. Any machine, that you put money in to win something, is rigged to keep more money in than it shells out. You can't run a company if you lose money.
The claw machine is like all those rigged carnival games, they are designed only to take your money and get your hopes up for the chance to get the fabulous prizes. I don't really know if boycotting them would make a difference but just be smart and don't waste your money on a parlor trick designed to have your kids guilt trip you into throwing away money on crap you can just as easily buy in a store for far less than you waste on trying to pick something up with the claw.
Each claw machine is different, but I know that they are definitely set up to eat your money. If they were easier, you would have to pay more. This is how the owner's of these machines make their profits. I don't ever play them because I know my chances are slim at best.
Why boycott it? Are they hiding anything? Nope. You and I both know it is not consistent, so what are they doing wrong? A scam means there is some deceit and hidden intentions involved. There are no secret intentions or rigging of the game. The information is widely available to the public.