Let's not only give them some of the "rights of persons" like "free speech", let's give them some of the responsibilities and consequences of being persons.
If corporations are persons then shouldn't they pay personal income tax? Many argue that corporate taxes are taking away from shareholders or are being passed on to customers. Well, aren't exorbitant executive salaries being decided by a self-selected board of directors taking away from shareholders also? Aren't the taxes being paid by my plumber or my barber being passed on to me? So, what's so different about corporations if they are considered persons?
If corporations are persons then shouldn't they be restricted severely for pollution? If I burn trash in my backyard or have a faulty furnace that is sending soot all over the neighborhood, won't I be called to account for it by my neighbors and the city? If I dump poisonous chemicals in my sink, won't I be called to account for it? If corporations are persons then shouldn't they be held to the same standards as physical persons?
If corporations are persons then shouldn't they suffer the same consequences for capital crimes? If a corporation commits such malfeasance that people die then shouldn't it go to prison? Prison in this case could be putting all its assets in escrow for the equivalent prison time. If a corporation willfully murders people and if the jurisdiction executes murderers then shouldn't the corporation be liquidated? Blackwater employees willfully shot Iraqis. The only consequence was the loss of some contracts and the company reorganized under a different name. Do you think that you or I could publicly change our name and address to escape punishment for any crime?
Remember the old adage: be careful what you ask for, you may get it.