Once I have found a bike that I really like , I keep it for quite a while. Like you, I have an '08 Strom 650 that I bought January 2015. Prior to that, I had a H-D SuperGlide for 9 years. I do rotate some other bikes through the garage, but keep my main bike.
Now cell phones - who in their right mind would want to have to change that out if you don't have to??