I didn't say it's an actual scam, though. It's a personal point of view, and I'm sure I'm not the only one seeing it that way. Also, being persistent means spending more time and money on something that would probably be cheaper if you buy directly. You'll be spending a lot more trying to get plush toys from claw machines than buying these toys from actual toy stores. There are people who are good in playing claw machines but I'll bet there are a whole lot more who just end up spending on tokens and getting nothing. It's generally a good place to waste time and money. Note the term "waste" 
Damn right, are they a scam? I am not exactly sure, but the odds are certainly not in your favor. God, these are awful machines. They have a worse grip than a newborn baby, and 9 out of 10 times when you pick something up, it'll fall right next to the exit latch. I've remembered them since childhood, and I don't recall ever winning anything. Can they be considered gambling? Certainly yes. Not all claw machines have stuffed animals inside; there are others that feature expensive devices, watches, electronics, or even cash prizes. There are even found in casinos, while they're spreading like a virus at almost every location.