> Miners can't just invent awithdrawal out of thin air that will sustain for 3 to 6 months in public.

A majority miner can, and is incentivized to do so.

> but [you] are not showing how DC is so very different a side chain is more vulnerable than any other part of bitcoin.

I’m sorry I haven’t been clear. My argument has nothing to do with the machinations of the sidechain. It could be a spreadsheet. How consensus is achieved on the sidechain is immaterial.

My point is about the locked coin on mainchain. That coin may be unlocked and spent by a majority miner (51%’er) who votes to give it to themselves. They can do so by building otherwise normal, valid blocks, reaping mainchain fees and subsidy along the way.

Such an attacker cannot take mainchain Bitcoin in the traditional sense (locked by private key) in the same way. To steal traditionally locked coin, the attacker must rewrite history. But to drain a sidechain, no history rewriting is necessary, just regular, profitable, forward mining.

Hope this clarifies. 🙏