That makes all the sense there is. It is the basic function of a market. If you try to fix prices, you will either have to much or too little goods. For instance in a business, if you fix wages below the market, the business will have problems finding workers. if you fix the wages at a higher rate than the market, there will be a queue of workers outside. If there is no quota in the gates (two way pegged sidechain), all workers will be hired in that business.
I'm sorry but I don't see the correlation. You'll have to develop your scenario on how market participant decide unanimously to converge to either chains.
They individually decide that, since the sidecoin is lower value, but can be changed for bitcoin at the fixed, high rate, they are better off converting to bitcoin.
the logic is sidecoin offers a feature that is not available on the Bitcoin chain.