Objections to BIP-110 (not saying I agree with all of them) can fall in several categories: (1) One my agree with the goal and object to the implementation: The focus on OP_RETURN may just push non-transaction data, more inefficiently, to other forms, and the 1 year sunset seems arbitrary. (2) Technical conservatism: There is no way to really test if, and to what extent, a change threatens consensus when real money is involved. Nor is it easy to test to what extent wallets or tapscript implementations have come to rely on long OP_RETURN's. (3) Non-transaction data may be good: Giving miners a source of income outside of transactions can financially diversify miner income, making security more robust against a crash in transaction demand. Bitcoin already subsidizes HODLers (who don't pay any agio) at the expense of transactors (who pay fees) as coinbase awards (and inflation erosion attendant thereto) decline, so such cross-subsidies already exist. (4) A meta-level objeciton: It is incumbent on the advocates of BIP-110 to answer these objections, and I haven't seen anyone do it in an analytic way driven by data, formal game theory, or even by analysis of monetary/banking history of previous eras. I don't think it is impossible to do that. Thowing out scare senarios (it is spam, nodes will cost too much, bitcoin won't be money anymore) is not sufficient.