Creating a new Bitcoin that is incompatible with the old would NOT massively destroy value in the old system. Look at Litecoin and other forks. Bitcoin holders collectively add value to Bitcoin (by simply willing to hold them and willing to pay slightly below the market price to add to their holdings), there is no single person who can change its fate. Even big rich guy's wealth depends on many poorer people to accept his BTC for the service they provide him with.
To switch to Bitcoin 2.0 all holders need to see no future in Bitcoin 1 and panic-sell into Bitcoin 2. If this happens, it's another huge bet (like going from USD to BTC), but the prerequisite is to Bitcoin 1 really be in trouble. Divisibility problem is not a fatal flaw, it can be patched, worked around, or counted in as an extra cost.
On the other hand, USD has tons of fatal flaws: it's being printed like crazy and it needs to be stored in banks that easily freeze, tax and censor accounts. Essentially, USD is not even an asset. It's always a chain of promises by bankers and presidents, who brake them constantly in various ways. Compared to USD, Bitcoin is infinitely better, so people are willing to make a bet that Bitcoin can replace USD. Imbalance like that is the requirement to start discussing a jump from BTC1 into BTC2.
To switch to Bitcoin 2.0 all holders need to see no future in Bitcoin 1 and panic-sell into Bitcoin 2. If this happens, it's another huge bet (like going from USD to BTC), but the prerequisite is to Bitcoin 1 really be in trouble. Divisibility problem is not a fatal flaw, it can be patched, worked around, or counted in as an extra cost.
On the other hand, USD has tons of fatal flaws: it's being printed like crazy and it needs to be stored in banks that easily freeze, tax and censor accounts. Essentially, USD is not even an asset. It's always a chain of promises by bankers and presidents, who brake them constantly in various ways. Compared to USD, Bitcoin is infinitely better, so people are willing to make a bet that Bitcoin can replace USD. Imbalance like that is the requirement to start discussing a jump from BTC1 into BTC2.