Also the difficulty scaling is important even if you don't take security into account: if you don't raise it, then the block mining frequency rise progressively, and then you end up with more and more orphaned blocks, until you end up with parallel chains that don't really converge to a single coherent one.
Imagine making a case for returning to the gold standard, when thousands of other choices for new precious metals, all with the same performance characteristics, were literally just lying around, and a network of drones would let you swap perfectly and instantly between those metals for pennies!
In that light, one can certainly understand the fervent contempt that Bitcoin maximalists hold for "shitcoins"; but a free-banking market cuts both ways. Barring a state blessing one chain and outlawing the rest, creating new cryptos and swapping between them won't go away. The proper way to measure the emergent "monetary policy" of crypto-currency is of the sum of all chains, not of Bitcoin itself.
3. cryptocurrencies stop the Austrian economics fetishism and index the coin reward to the mining difficulty. That means getting rid of the fixed coin supply.
That would stabilize the price of the token a lot (since price going up would increase the mining appeal, thus expanding the money supply, driving the price down) and also make it much more usable as a mean of payment (the number of token in circulation would grow in parallel with the growth in users).
Obviously it's not gonna happen, because those people have spent a decade convincing themselves that deflation is good and fixed money supply is the righteous way to manage a currency.