I think it makes sense not to have a vote if you're not eligible by residency requirements, as long as you are not contributing to the taxes as well it makes even more sense. In the US, I'd be worried at not having national representation because of how invasive the country is world-wide (and don't even get me started on FACTA and the problems that causes for expats), although even having national representation, i.e., the ability to help elect the president, doesn't really give much comfort. Canada is a bit easier to get along with and probably not much of a detriment to its citizens abroad.
I use very few services of the US. People would argue that I "enjoy" the protection of the US military and consular services while being an expat abroad, but at least the military part I see as quite a detriment to my existence. I don't get into situations where I need rescuing by the US military, but if I did the likelihood of being rescued by a military operation isn't really all that good. In fact, with all of our world-wide meddling in the affairs of other nations militarily and economically, I'm often made a target instead. The consular service will get in touch with local authorities and "work with them to watch the situation" in case I'm in trouble on foreign soil. And any consular service I've used in the course of normal expat life has cost me money out of my own pocket.
What do I get for the taxes I pay while living in a foreign land? Sure as hell not what interests me.