One I heard Imran Khan saying that In Pakistan when I watch children playing, they fight alot in between the match and after every fight the bowler becomes more angry and tries to bowl even faster delivery than the previous one.
The second reason I read some where on internet that most indians are vegitarians as they don’t eat cow meat, which is among the major sources of Protien and strength.
I think Ravi Shastri (or sanjay) mentioned it that it depends lot on the legends which you had in the past. A lot of Pakistani youngsters look forward to become like Imran Khan, Waqar Younis, Sarfaraz Nawaz, Wasim Akram, Shoaib Akhtar…etc.
Re: India not producing fast bowlers like Pakistan
This was a debate of 80s. Very old topic.
Lack of protein diet can be an issue, but Indians do take alternates of meat. I think it is the aggression (josh hi josh no hosh) in our nation that helps us producing high quality fast bowlers. In last sixty year we never had problem in this area, where as India have only managed to bring Kapil Dev out, who was a decent medium pacer at the best. He had a good brain and was a thinking bowler with consistency. Thats how he got so many wickets.