Why Doesn't Earth Have Rings?

Using the Roche Limit to Make Earth a Ringed Planet
https://gizmodo.com/using-the-roche-limit-to-make-earth-a-ringed-planet-5931098

a nifty thought experiment: the Earth with rings
http://josephshoer.com/blog/2009/11/the-rings-of-earth-part-ii-implications/