The free market provides a solution. When the block size fills up, people will pay higher transaction fees to get their transactions through. Free riders paying zero or low transaction fees won't get their transactions processed.
The block size can only be increased if the big miners agree, and it's not in their interest to increase it.
If it hits 0.1 BTC to send one satoshi then the only people left will be miners.
The free market will go somewhere they're not going to be raped. BTC is purely optional and sometimes a prime pain up the arse. It wouldn't take all that much for people to abandon it before it gets going.
Kudos, a big +1 here gentlemand.