Bearing Burn Out
Welcome to the forum Art. There is certainly a wealth of knowledge and experience here.
I too am curious about your post. My table mounted router has a soft start feature which reduces the shock on the unit during start up whereas my table saw with a hard start almost jumps when I turn it on. However, I start the router, it ramps up to full speed, I work with the piece, I turn it off. I really don't understand how this can cause bearing burn out. When I use my plunge router it follows the same process. The only thing I've noticed with my fixed router is that some sawdust can collect below the collet but I clean that when I change bits.