I've owned five motorcycles with Linked brakes. It is not linked brakes per se that is the problem - it is the Concours linked brakes that is the problem. I totally agree with the comments the OP and others have made. After many, many years of riding, this bike broke me of using the rear brakes. I still use them some and am always amazed at how poorly they work. As others have said, if you are on the front brake and the rear, the rears give you a sudden jolt of braking that is very abrupt, uneven and unexpected.
When I first changed my pads I thought it helped a little, but after a couple of rides I realized it was wishful thinking. The problem is in the system and I feel like the only fix would be to put some really bad pads on the rear that are so ineffective that they just don't really do anything except to make you think you fixed the problem.