Perhaps another way of looking at this problem is the gitbhub thread below. If, as the chief scientist G.A. claims, it was only due to the heroic efforts of two people to downgrade to a earlier version of the BTC blockchain that saved the bitcoin P2P network from disaster, then it stands to reason that bitrot could cause a repeat of this incident, in that a 'buggy' version of the bitchain is adopted (namely, one with bitrot) and if there's no heroic people to step in, the system crashes.
Another way of looking at it: RAID systems have on rare occasions had bit rot that propagates, bringing down the whole system. In theory this is impossible, but in practice it is not. Might the same thing happen with bitcoin? Time will tell. I'll leave the last word to somebody else.
You cannot corrupt the blockchain. The hashes in the blocks make that impossible.
The only reason those 2 people downgrading worked was because the
majority of the miners also downgraded and verified that their copy of the chain was identical to the everyone elses. It only worked because thousands upon thousands of miners verified it as correct. Bitrot is impossible.
