The rule of law is not a tool of oppression; it's a check on the people with power and guns.
The revolutionaries do not have the power. So throwing away the legal system is far, far more likely to just lead to an unchecked re-entrenchment of whoever is in charge, not a new system.
If things are truly, truly catastrophic, maybe that's a risk you're willing to take. But since the average American is not, in fact, dying in the streets, most really want to continue living their lives in relative prosperity and relative freedom.
We all have to work to eat, but nothing says people legally have to do a good job in most positions -- and it's easy to get away with if you can talk a good game. The idea is that because the rules aren't enforced against the people at the top, why should the people at the bottom help enforce them against their peers? If the police are a tool of the oppressive state, why would you help them in any way? If you're systemically oppressed, why would you not be dishonest and game the system in every way you could?
Corporate leaders are generally on negotiated contracts that protect them in the event of genuine incompetence (the "golden parachute"), which reduces the motivation for political incompetence. Regular workers and middle management rarely get that luxury.
Fixing this requires having an honest discussion about how we distribute wealth between workers and owners. But it's not surprising the people who currently take the lion's share are actively preventing that conversation from happening.
None of this is particularly radical, and it's basically what Bernie Sanders is running on. His positions are solidly center-right by European standards, so it's not like he's proposing some radical thought experiment.
By the way, I don’t believe such an action is the right way to make change, I just think that it’s a very privileged position to take that most people have something to lose by the demolition of our current institutions.