https://doc.co/6rzZ6BJust made a short PowerPoint presentation of Synthetic fork. It combines the benefit from both soft fork and hard fork, and is a new way to safely upgrade the bitcoin protocol. Welcome with your comments!
The idea is formed over several months, but the latest breakthrough is from this thread:
https://bitcointalk.org/index.php?topic=1649899.0 I guess it may be better than a hard fork but it's still worse than a soft work.
It still has the big problem that hard forks have (and soft forks don't): every miner, user, merchant, everyone, would have to update or else they are left behind.
Also, you are forcing everyone to update, but some may not... so some miners may still mine the original chain (they may stop after "phase I" and continue after "phase II") and it may still split.
Following your logic, miners can also mine the original chain after a soft fork as well, because phase I is exactly the same as any soft fork
And just like a soft fork, all the miners have to upgrade, otherwise they lose income, but the rest of the nodes are not obliged to upgrade, they can keep running the old version, they just get a function disabled client. This is also similar to a soft fork: old clients can not verify the new transctions. But this is actually safer than a soft fork, since in soft fork, non-upgraded nodes would just let any new format transactions through without check their validity; but in synthetic fork, these non-upgraded nodes would not let them through, they give a clear signal that you must upgrade
Notice that financial system is very different than consumer software. If you don't care about your money by not upgrading, then that is your own problem, no one should take care of your loss
