You can do that, but you still have a battery that will eventually become a problem. I prefer my wired devices not having a potential bomb on board :) As I generally use old devices with worn batteries this is likely to become a problem much sooner, and much less of an issue to stick a screwdriver in and start tearing parts out of the device. Of course you're not going to do this to your brand new tablet under warranty.

However, doing that you do have the benefit of having "UPS" protection of course (how much depends on the charge cycle). In my case this isn't really a problem because if my power is down there is not much in my home left to control that still works.