Imran's initial selection was bcuz he had friends/family in high places, as is the wont of Pak selection. He did not even have his run-up mapped out. In fact, his early ambitions were as a batsman (dreamt of walking out to partner cousin Majid), but was discouraged pursuing that line due to the surfeit of Pak batsmen. His only way to the Test team was as a fast bowler.
After his early failures, he could have given up, but by dint of sheer perserverance and hard work, he went out to become......the first genuine fast bowler from the sub-continent and heralded an era towards attack, far removed from their inherent defensive mindset.
Imran was the pioneer, the leader who broke ceilings. Were it not for him, we may not have had a Wasim, Waqar, Shoaib.