100% true. "Both sides" arguments exist SOLELY to deflect from awful things done by Republicans, or detract from positive things done by Democrats.
Not once have I seen it deployed for any other purpose.
Edit for the pedants: I should probably have not led with "100% true" before the sentence where I clearly stated my position. Although I think the delta between what I wrote after that and what is in OP is a difference without a distinction, if some of you want to feel like you really got me, you go right ahead.