That is fair and constitutional. I would rather have to proceed through an indictment before being brought to trial instead of just being dragged to court immediately on a serious charge. But the indictment means nothing, only probable cause.
Amendment V of the U.S. Constitution.
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury, except in cases arising in the land or naval forces, or in the militia, when in actual service in time of war or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
I see & agree with your point, but it still seems counter-inituitive. If a prosecuter can play a GJ all he wants, without letting any contrary evidence in, then the GJ merely becomes a formality step in being dragged to the court on a serious charge??