The higher the compression ratio, the hotter the engine runs. Lower compression engines are designed more for boosted motors. Reason why higher compression engines are built for more N/A applications are simple. Lower compression numbers run richer. The richer the engine runs, the less hot it runs. The more gas in the air fuel mixture the wetter it is. This in turn, helps to cool the engine more naturally than running higher compression.
Higher compression ratios tend to be for N/A motors, because they make power more naturally, than other means like super chargers or forced induction. N/A engines produce power on a means where its more free flowing, and the parts can handle the heat with better tolerance. Turbo engines force air and gas into the combustion chamber creating more heat than normal. Which is why they need to run cooler, or lower compression numbers. If they ran higher compression numbers, it would grenade and explode due to heat abuse.
Ideally 9.0 compression ratio is perfect for turbo and supercharger motors. Even 10.0 compression is for turbo motors. 12.0 and 13.0 are more ideal for higher compression N/A engines.
