Using fake data in the registration process is against the EULA of pretty much any service offered by companies nowadays. Also, with readers that need activating, as far as I know you have to go online with them if you want to upgrade their firmware.
That would allow companies to get to know your reading habits, and it would also allow companies to lock you out of the reader and force you to enter other / real data if the data you entered initially were found to be fake. The former is something I very much try to avoid. It is nobody's business what I read, how often I read it and how long it takes me to do so. The latter is just an unnecessary inconvenience that can be avoided by disregarding such readers. Jailbreaking / rooting would be another way around these issues, but is not an option if there are no such methods for a certain device yet.
With software on my PC, I get to choose if I want to install a certain program or not. I take the same liberty picking a reader.
@Quelch
I'd probably pick one too, but having to recharge it that frequently is something I just can't get myself to feel comfortable with. Having to recharge a tablet some time during a 10 to 12 hours reading run is a total immersion killer
Granted, I don't do it that often, but it happens.