Yes, the quality of the agents has changed for sure. However it seems the population now are easier to polarize, perhaps because media is so prevalent in our lives. There have always been groups that went to the extreme with the "for or against" attitude, it seems now that those groups are far larger.

And again, if you're not interested or undecided, then you're the enemy, whereas in the past you would have just been ignored.

I wouldn't be so sure about quality changing, rather it may just be visibility