[GrangalanJr]

In Bryan Magee's Confessions of a Philosopher, he describes exactly this habit as the thing that impressed him most about Karl Popper.

I think some fear that giving an opposing position (X) the best possible interpretation, or responding to the smartest supporters of X, might make their own position (Y) look weaker by comparison, perhaps so much so that some readers will decide to buy into X rather than Y after all! "Strawmanning" is the easier route, as it saves one the bother of having to come up with powerful or detailed counterarguments.