Supreme court is a stupid idea in the first place. No one should be given such an important position for life. In fact, I don't think a person should be given that much power period.
If there's no hierarchy in the court system you have no way to know what the standard will be for interpreting the law in your jurisdiction. It turns courts into easy targets for mafia
standards can be agreed upon among peers, i.e. without a supreme final arbiter. (e.g. technical standards)
What incentive is there to keep judges from making "non-standard" rulings? If there is none then you need some kind of enforcement.
