The thing you have to understand about the ardent small-blockers is that they really genuinely believe they are protecting Bitcoin from a very real existential threat. If Bitcoin's security properties get diminished, there's no going back, no undoes or fixing the problem. It is a permanent change that irreparably weakens Bitcoin.
Very true.
Ironic, however, because this is precisely many people's opinion about
Segwit. 6,000 lines of code that completely alter the blockchain structure, change the transaction format to "anyone can spend", and force the entire bitcoin space to rewrite millions of line of code (exchanges, mobile+hardware wallets, utilities, explorers, etc.)
Of course there won't be any bugs or exploits created along the way [/sarc]