I am one man on the dark side that cannot take this rebellion task alone. Regularly through my GD.SE life I prefer a question to have more than one tag.
I would like to encourage site members to actively edit questions that have one single tag. By adding tags it can assist in filtering search results.
An old question that has become active today: "How to fill path in Illustrator with average color (like in Ps)?" has a comment left by Joojaa: "There is a near duplicate question some where on GD.Se that used a script to do this" that I was encouraged to see if I could post it as a comment or see if it actually warranted a closure as a duplicate, but I found in my search that we have a number of questions that have one single tag.
If we want a better site experience and a way to filter out our searches a good solution would be to use more than one tag on questions. Plus if you have less than 2 k rep you can get a +2 (bribery almost..)