I believe I've watched or listened to at least two different debates where reardencode (Brandon Black) took the side which I also would take. In both of those, I felt that he did not necessarily do a great job defending the viewpoint. Maybe we just think about things differently, or perhaps his debating style doesn't resonate with me -- but I was reluctant to read this opposition piece he wrote regarding BIP 110 because I thought perhaps it would be a let down.

This was not the case. I found his defense of Bitcoin, the open, permissionless system to be fairly compelling. I believe I had heard many counters to the primary argument he puts forth here, but none of them seem worthy of risking the permissionless nature of bitcoin -- which is precisely what we do when we specify a certain class of widely-used transactions as "bad."

Bitcoin is an open-access, censorship-resistant ledger to which anyone can write entries if they are willing to pay fees sufficient to convince block template creators and miners to include their transaction. The fundamental value of Bitcoin vs. all other ledger systems is the aforementioned open access. Without it, Bitcoin’s ledger has no more value than the bowling alley scoreboard.

Because of this fundamentally open access, we all know that Bitcoin will be used by those we hate. Much like the principle of free speech, which is meaningless unless it applies to speech that we don’t like, Bitcoin’s open access would be meaningless if it only applied to transactions of which you or I approve. I will therefore assume that we do not want to be in the business of inspecting how other people structure their ledger entries any more than we want them inspecting our entries.

BIP110 proponents might say, “Sure, but that only applies to monetary entries! What about these non-monetary entries?”, but the reality is that there simply is no such distinction. Every transaction made on Bitcoin is made by satisfying the conditions of some locking script to make an entry in the ledger, which consumes input coins and creates output coins. The fact that one transaction’s scripts are larger or smaller than another is of no relevance to me as a Bitcoin node operator or user.