I think the problem with this is that people would theoretically be able to sell one of their two licenses on the “black market”, which appears to happen with other software; see Daniel’s post above.
That said though, I’m actually with you in that a dongle is not such a bad thing — I kind of like my iLoks which allow me to move from computer to computer without having to license / unlicense anything on the internet. If the transfer of the Dorico license from dongle to machine and back is going to be an easy operation (as Daniel indicated it would likely) then I’m fine with it.
As we’re getting closer to the launch, I’m sure there will be many instructional videos on setting up scores / players etc.; maybe Daniel can do one where he demonstrates how to transfer the license between machines, which should hopefully put a lot of angst to bed.