Constitutional personhood

Most conservatives balk at the notion of the "living constitution." And most liberals detest the idea of corporate personhood. Yet if a corporation can be alive enough to be "person," and a corporation is created via a legal document signed and filed by one or more people, then why isn't the constitution similarly a person capable of evolving? Since a corporation does not to file amended articles of incorporation to change its business focus, why should additional amendments to broad articles and amendments to the constitution be necessary?

Likewise, if the constitution's words and meanings are capable of changing as society's standards change, then why can't a corporation have changing principles that drive it? For example, Apple changed from a computer maker that also sells software to run on its machines, to a company that sells music,  ring tones, movies, apps, services, software, phones, tablets, music players, as well as laptops and desktops. 

Both sides a bit wrong on both issues. The constitution is alive in some respects and corporations are limited beings with limited rights.