Food habit and climate are the most important hindrances of producing quality fast bowlers.
We see outside the Indian subcontinent, almost all cricketing nations produce quality fast bowlers regularly. In the subcontinent Pakistan also make enough first bowlers. But Bangladesh and India fail to produce quality pacers. If we follow carefully our food habit and condition is the main cause of it. Although Pakistan is in same subcontinent they don't eat rice like us. Even their climate is dry and also a little different from us.
Do you think any reasons?
Think a lot, speak a little.