I think you are reading too much into this, and worrying way too much...!!!
It is not common at all, i have friends that snap boards, but they are part rats and ride 5-7 days a week, 20+ weeks a year, and maybe snow a board every 5 years on average...!!!
I have been boarding 7 years, and hit the park regularly, and have never snapped a board, in fact i would say, when i have finished with a board it is still in pretty good condition, and have a 6 year old K2 Jibpan that i still use in the park...
Just because you buy a park board does not mean it will last longer in the park, you have to ride really hard and often to do that sort of damage, or be extremely unlucky...
Height 5"11, Weight 200-210lbs, Born 1969
Regular Stance, Ability NOT GOOD
2102/13 114 days
K2 Jibpan 153, K2 Fastplant 154, Ride DH2 158, Endeavour Vice 155