It's not necessarily that they get wrecked any more than any other newer car (though, they might), it's that the insurance company's threshold for writing them off is lower than most cars.
When you can buy them brand new for $12k (or even $10k if you shop for the right deal), their used value is on the order of $8k or less. (I paid $6800 for mine with only 30k on it) Figure body repair costs are a minimum of $500 per panel. Front end collision is going to take out the hood, bumper and two front fenders, plus straightening and repairing of the understructures. So, any solid front hit is going to cost at least $2500-3000 to repair. Add another $500 for each airbag that deployed. Pretty easy to top $4k, which is over 50% of the value of the car. Throw in a bent wheel, broken axle... broken headlights... broken windshield... dented roof panel...
That's why you'll find these in the salvage yard a lot sooner than, say... a $25,000 car that an insurance company would readily put $10-12k into repairing.
They potentially get crashed more frequently because they're cheap. Who buys cheap cars? Young people. Who is more likely to crash a car? An inexperienced younger driver. Couple that with extreme eco tires that make the car decidedly NOT stop like a sports car... there ya go.