Or you’re doing a conversion on a frame that wasn’t designed specifically for the tires you want to run? maybe it’s a road frame with very short stays designed for the use of very skinny tires, maybe has no dimples on the inside of the stays? Petty common for 70s era road frames, which are very popular choices for conversion. You could easily enough say, use a different frame, but none the less, there are in fact reasons why you could have little room for adjustment and it’s not a ‘frame designed by idiots’. But you’re welcome to your foolish opinion, I guess.