The problem is not he follow or never follow his father.
The problem is when he take over as PM, the internal and external conditions have changed. When conditions change, there will be implications.
What PM Lee failed is he failed to recognize the S'pore population have become more educated, different thinking, values, and behavioural tendencies.
He also failed to recognized the social values is getting outdated. Some of the Principles are outdated and no longer relevant.
Technology have advanced, he failed to recognize that he can utilized them and there is a need to change system approaches, thinking, and political ideology. After 2008 crisis, the free market fundamentalism philosophy is discredited, pareto principle without wealth distribution will widen income inequality. The assumption that market will auto correct problems and wealth will trickle down to majority is false - Corporations are hoarding the financial resources.
He also failed to recognize new emerging problems caused by immigration policy. Basically, he sticked to status quo and his father's approach.