Those are good points. On the flip side, regarding lower ticket races, if you do take the time to educate yourself about one your vote is going to matter more there (and they might well have a bigger impact on your life, to boot). Your vote still won't matter (outside Washington County, Arkansas, anyway: http://www.co.washington.ar.us/Modules/ShowDocument.aspx?doc...), but a pattern of people not voting certainly will matter.
http://www.bloombergview.com/articles/2014-11-04/five-good-r...
http://www.dukechronicle.com/blogs/bigblog/posts/2008/11/03/...