That's a great, but a complex question that I'm not qualified to answer. I'm sure others can chime in but here's my take: SK's democracy is still in its making. Even though the country is thousands of years old, its first 'democratically' elected president only came to power in 1948. That's after my parents were born.
I said 'democratically' in quote because nearly all presidents that came into power leading up to 1993 were essentially quasi-dictator and military heads. Even into the 1980s, South Korea had a hard core labor camp in middle of Seoul that housed tens of thousands of gang, anti-government or social activists, and criminals who were sent there without due process. No reliable death count exists, but it's estimated to be 500+ if you count people that suffered premature death after release.
So if you are 40+ like me, you remember what it was like to live in South Korea before the good times that we're all familiar with now. You remember your college age neighbors going out on street in 1980s participating in anti-government protest throwing Molotov cocktails. You remember anti-North Korea curriculum in grade school published by ministry of education. You remember not having true freedom of press and had to self-censor even until 1990s. You remember the sacrifices people made before voting in their first true true democratically elected president in 1993.
People are empowered to make changes, because they know they can. They've sent nearly all presidents elected since 1980s to jail for corruption. It's almost a running joke that if you become SK president, your next stop after office is behind bars.
9th term - assassinated in 1979
10th term - coup and forced out
11th & 12th - jailed and sentenced to death but commuted
13th - jailed and sentenced to death but commuted
14th - family member jailed.
15th - sentenced to death by 11th pres, but commuted.
16th - jumped from mountain and killed himself.
17th - jailed and released.
18th - jailed and still in prison.
19th - still serving.
There are millions of Koreans who still remember their 1st president including my parents.
Also, living right next to China and below warmongering NK, people subconsciously know that everything can turn on a dime; you don't want to take any chance with an incompetent one at the top helm.
I think this explains the psyche and behavioral aspect of South Koreans.
The decision to jail the Samsung execs is probably just as complicated too so I won't do justice to the topic. The current administration is very socially progressive. They've been trying to tackle increasing wealth gap issues through real estate tax rules reform, minimum wage increase, and enacting more labor protection laws. As much as Korea appears wealthy from outside, loots are not being shared fairly, people are losing hope, it went from saver nation to zero-saving nation in 20 years.
This corporate crack down is an extension of that. People are pissed and they want to see blood and government is obliging.
Someone once said, Korea still has a dictator and it's the people.
Again, this is just my personal view. ;-)