Calling part of the government illegitimate is a very slippery slope to justifying trying to overthrow said government. You can say they are corrupt, you can disagree with policies, but saying illegitimate is cause for extreme responses.
Do you always judge the validity of a statement according to the implications of it being true, or do you get to do it just this once as a treat? Further, how does saying a court is "corrupt" not call for "extreme measures" but referring to it as "illegitimate" does? What's the meaningful difference?
Calling members of a court corrupt, means you can pursue legal action against them, write laws, impeach, etc. calling the court itself illegitimate, implies the government that put them into power is illegitimate. Calling government illegitimate is the first move of revolutionary groups.
I'm sorry but no legitimate court would hide the majority of their income. Those aren't actions of an institution we should place this amount of power into.