"I assume this has something to do with the fact that information from the long tail is substantially less searched for than stuff within the normal bounds...It seems like the web is being optimized for casual users"

In other words, the internet is becoming more of a collective and caters less to the individual.

If you have a special interest, then who cares? You should just adopt more normal hobbies. If you have a unique political viewpoint, then get over it and join one of the major parties. If you are oppressed, then it's fine as long as 95% of the people are content (don't worry, we'll carve out a few protected classes so that the pictures still look diverse).