Why my script only works with some object selected ?

This addon change the visibility of some modifiers and exchange the layers active. Works nice without be add-on (like script), but being add-on only can be invoked If there is object(s) in the active layer, or selected. How I can make it work with or without be selected objects in the active layer ? Thanks.

http://www.pasteall.org/40309/python

EDIT(2): The problem isn’t an object selected or not, simply the addon not can’t be invoked if there is no objects on the layer active. If also if there is no Object selected.

remove the entire classmethod poll() from the operator

Thanks you a lot, works now!