From the Nikkei article:
> The older Miyazaki, 82, and Suzuki, 75, have been discussing the succession process for a long time, according to the two companies. Miyazaki's son had rejected the role, saying it was difficult to operate Ghibli alone and that the company's future would be better left to others. Nippon TV, with which Ghibli had deep ties, became the natural candidate.
Additionally, conservative is loaded term it's not really helpful in getting across what they feel without additional description. They're possible old school conservatives but even that probably comes across wrong as how they themselves would want to be described.
I have no doubt that Goro wanted to be his father's successor (why would he have made multiple films under the Ghibli umbrella), but his father clearly recognizes that Ghibli has a potentially larger future than becoming a lesser studio under his son.