With policies like these, companies account for the % of times abuse is likely to happen. Retailers and manufacturers spend millions analyzing buying and returning patterns and factor that into prices.

So "abuse" over time could cause prices to increase by a small amount. However, not hassling people over things that rarely happen increases loyalty, which increases volume, which increases the discounts a retailer can get from a manufacturer...

The vast majority of people don't need to benchmark video cards or want to "rent" products - they buy things because they need them and that's why good customer service exists.