[corbulo]

If Corporations weren't people you wouldn't be able to sue them. Read more.

[majormajor]

Corporations aren't the only non-individual entity you can sue, and the ability to sue could be extended separately from other person-like rights or responsibilities (see, for instance, that corporations can't vote).

[red-iron-pine]

The government isn't a person, but I can sue them.

Hell, I could sue companies before the supreme court determined they're people for election campaign fund purposes.