I am over-generalizing, perhaps, but...

There are few leftists who can articulate what anyone outside leftism thinks, and so they prefer strawman arguments and insults. Disagreement results in being charged with heartless, selfish, fascistic disregard for others.

Some right-wingers can articulate libertarian and leftist ideas, but they are rare. Expect to be called a godless commie traitor who should move to Somalia most of the time when you challenge their beliefs.

Libertarians often just mock both the left and the right, but by and large, can explain what they each believe and some reasons why they may believe it if pressed. But we get tired of trying to get the idea of liberty through their thick skulls. So entertaining ourselves with mockery seems like the only thing left sometimes.