The negatives that bother me about not changing the block size limit are...
I very much doubt any of the items in that list are valid concerns. The only
real broken promise of a fixed block size are the eventual high transaction fees. It is still not clear that this is a bad thing. One thing is for certain, however. A fixed block size should deliver Bitcoin's promise of "largest hash rate of any block chain"
You didn't actually address any of my concerns, you just dismissed them all. Any reasons why?
I gave a reason to doubt the assumption that a fixed block size will necessarily lead to greater hashing power here: