I can't exactly see people rushing to convert their old (relatively stable, perhaps deflationary) money to the new one. Therefore, I can't see many businesses s

I can't exactly see people rushing to convert their old (relatively stable, perhaps deflationary) money to the new one. Therefore, I can't see many businesses stopping to accept the old bitcoin. Rushing to convert "old network" BitCoins into the new network (or dollars, or whatever), and businesses stopping acceptance of them is exactly what will happen. Don't forget the primary function of money is to allow people to trade it for things they want. Unless you're a staunch ideological libertarian you will want as much of your "money" as you can get in whatever system offers the most goods and services. Otherwise you have lost value. That system will certainly not be the one containing only sparsely geographically spaced libertarians.