This is why: species like this this shark/eel (it has 300 teeth!) have survived for an estimated 80 million years. It has outlasted just about every other living species.
This is the type of organism that thrives at life. It is aggressive, lean, dumb, and impervious to reason or sentiment.
Sadly, in the world of politics, it is often the ideas and memes that share the same characteristics that win out (i.e. gay marriage is evil, immigrants are ruining the country”, “your religion is wrong”, blah, blah).
Just like this thing, those ideas can only chomp away at whatever is in front of it.