Narayana Murthy was an entrepreneur. He worked for himself. Likely that he worked 80-90 hours himself (or he might not have kept a count). Even while he was resting, he might have had thoughts of how to make progress with his mission. He breathed and lived his company. He was not alone in building Infosys. He had partners. And those partners though they had complete trust in their mentor Murthy, it appears like, they did not have the same level of commitment or the burning desire of Narayana Murthy.
For anybody working on his mission, hours do not count. Forget the corporate world, go and check with a Sadhu doing sadhana in the foothills of Himalaya. He too would not count the hours. He is dedicated towards his mission. And he does not seem to care about measuring it with the hours.
Then there are others who work for money. They are largest mass in the society. They work for others to earn their livelihood. If they too are ambitious, they won't mind working 70 hours a week for the fixed pay they get at the end of the month. That is because they see value in the extra hours they are putting and they expect that it will be paid back in future through a better job or a promotion. If they enjoy the work, again they would not mind spending all of the awake hours in the office going to home only for sleep.
But look at factory workers. They expect to be paid for overtime. They need an incentive for the extra efforts. If a leader gives a motivating speech and ask them to work extra hours without compensation, it will build resentment rather than they coming forward to do what is being asked. That is because they question the purpose of doing additional work than stipulated. Fruits of their labor will be enjoyed by shareholders of the company and the management with hefty bonuses. What the labors get would be peanuts. If the purpose of work is to exchange it for money, which is the majority of workforce, Murthy's advice won't be taken as a good advice.
I believe Murthy said to work hard with an intention of building a better India which in turn will help us better our lives. So he said avoid instant gratification. But for an ordinary person, a better might not happen in his lifetime so he demands to be paid now instead.
If you compare India with other countries, a person living in India would not have to struggle a lot for survival. Much of the basic necessities needed for survival are present throughout India. Climate is not harsh. And Indians rarely had the ambitions of going out and conquering the world. They were peace lovers or in other words they were lazy enough to do anything beyond survival. What has been passed through hundreds of generations may not change in a hurry.
Those very few who want to change things will love Murthy. Some will criticize but the most will ignore what Murthy has suggested. For them purpose of life is to do the minimum work needed to survive. If everyone works so much, who will watch Movies, Cricket or stage a protest? An ordinary person would have watched more moves than Murthy had done. Any average person in India can name all the players in our World Cup Cricket team but Murthy despite his huge memory would struggle to do so.
Purpose of life is different for everyone. It is difficult to be like Murthy. Instead they do what is easy and please their senses.