I think that the ability of getting XCP with proof-of-burn should be postponed to the time when there will be a stable client. It will help the distribution of the coin. If not there will be another distributed exchange with large-holders(who risked their money into a thing that didn't worked at the time) which will be very unhealthy for the counterparty system.
The problem with postponing proof-of-burn is that, since Counterparty is open-source, it is highly probable that someone else will just take the code and start the proof-of-burn. There isn't a perfect solution, so we have chosen what we think is the best solution.
For those who are willing to take on the risk of using the unstable client, there is an early-entrance bonus (50% with a linear decrease over the course of roughly a month). Again, this is not to say there isn't risk, we are just trying to reward those who are willing to take on the risk.
