Do non-profit motivations equal corporate motivations?

The Mozilla home page has some blather about how because they are a non-profit, they are not manipulative in order to enforce market needs.

As a non-profit, we’re free to innovate on your behalf without any pressure to compromise. - "Welcome to Firefox," The Mozilla Foundation

Then why is it, when I specified an alternate location for the Mozilla 10 installation, the installer over-wrote an entirely separate installation of the Mozilla 3.6 software?

That's the kind of thing Microsoft would do.

Then why is it that we are urged to switch over ASAP with nag-windows, much like Adobe would use?

Could it be that since both corporates and un-corporates (sorry, non-profits) have similar motivations, which is to force people to use the products that are convenient for them, that they act similarly?

It sure seems so.