If you rise the block size limit, then you're destroying the fee market competition, which is your only source of income as time goes by. And that's without even mentioning other issues that arise with that decision.
- "B-b-but, isn't 10 or 20 MB enough to sustain the fee market while alleviating the scaling problem?" Maybe, but that's what you do: you alleviate it, you don't solve it. It will still be expensive and extremely slow for point-of-sale.
With 10 times bigger blocks, fees still won't be zero. There will be more transactions and more people could use Bitcoin. That means more people pay fees, so the total fee will still pay
millions to miners.