Admissions are sort-of Pareto distributed, so most people admitted were on the edge of being rejected. Since there is a bit of noise in the process, this is why any one individual applying to 10x as many places of a similar tier will be more likely to get into one. But then when everyone does it, no one is more or less likely to get in except those that are actually cooperating with the admissions office. You're burning down the commons for a fleeting bit of warmth. Might I suggest installing a furnace in your house instead?