I feel like it's hitting a bees nest but I kinda still don't see the harm in making a variable block size - on paper. I get that it's a linear solution to an exponential problem ("blockchains don't scale") but playing guessing games with unpredictably high fees is one of my least favorite things about BTC- I feel like it could still alleviate it even if it doesn't solve it.
Granted the best argument I've heard against any huge change like this is you will have an effect on the value of bitcoin so you're better off doing nothing (the value of Bitcoin is partially due to it's unchanging nature). Seems like a great idea as a store of value, I'm not sure if that's a winning stance for a technology.