Increasing capacity by ANY amount is scaling. In the world of tech, we scale to the limit of technology and demand, we don't need to scale things to infinity to have a scaling solution.
Bitcoin Cash YESTERDAY, put thru blocks of over 10kb and even blocks of over 20mb to prove that it is feasible to process that many TX at low fees simply by not hitting the capacity limit and thus imposing fee competition. BTC is the cruel joke at such low limits so close to being triggered and setting off competitive TX fees.
With these trade-off :
1. Higher cost to run full-nodes
2. Leads to less full-nodes
Because it will not have consensus.
Because it will cause a chain-split again.
Because it will divide the community again.
Because hard forks are exclusive and they shut out nodes.
Bitcoin Cash is available, if you want the bigger blocks.
We just had a hard fork with the inflation bug, nodes that didn't upgrade got shut out. That's actually good. why would you want to include retarded nodes?
Actually, it's not hard-fork since there aren't any protocol changes, but
fix bug which could make accidental hard-fork since older Core version accept invalid block and miner would build another block above it.
Even SegWit soft-fork had some problem that Wind_FURY mentioned.