Do I blame all blacks for the crimes of one black person? No. Di I blame all jews for the crimes of one jewish person? No.

I don't know about you in particular, but by their rhetoric and positions most of the alt right absolutely does.

I want to add one aspect. If some guy commits a crime, I will ask the question "why did he do this?". I will try to find out what lead this guy to commit this act. Here you often find systemic problems and then one needs to ask the question "is our society (or at least parts of it) failing?". I still do not blame everyone for this act, but if you really want to "solve" these issues (or at least reduce these problems), you will have to look at the big picture and not only focus on the perpetrator alone. This brings me back to my original hypothesis, one can not completely separate an individual from his environment.

You're basically describing postmodern liberalism. You bring up any problem, the alt right solution is generally to persecute some minority group. Take wealth inequality. The liberal solution is labor rights, social programs, and corporate regulation while the alt right solution is to persecute the jews. Same with violent crime, that alt right's suggestion is just to persecute black people.