Evans was good at what he did. He had good hands out of the backfield,(especially as a checkdown) he could run successfully when needed which was usually short yardage, and he did a great job blocking both in the running and passing game. With him gone the pats don't have a true fullback, and in times past when they didn't they struggled in short yardage. The pats backfield has been injury prone in past years with the exception of Evans....he never missed a game in 3 1/2 years.
Evans is gone and the pats move on. However wishing the pats could have kept him (which they tried to do, just not at the price he got) isn't "borderline psychopath"