Opponents argue that anyone paying the transaction fee has bought the right to use the space however they like, and that miners and node operators should not be deciding which transactions count as legitimate.
Bitcoin mining firm AntPool mined the first non-signaling block, which the rest of the network accepted and BIP-110 nodes rejected, and a miner using Ocean produced the alternative that the breakaway chain followed instead. (A miner is an entity that uses massive computing resources to maintain bitcoin and process its transactions, earning newly issued bitcoin and fees for the work.)
AntPool and Ocean are mining pools, where many operators combine their machines and share the rewards.
The stall has a mechanical cause that is hard to escape. Bitcoin recalculates how difficult mining is every 2,016 blocks, aiming to keep blocks arriving roughly every ten minutes.
The breakaway chain inherited bitcoin’s current setting but has a tiny share of the machines, so its blocks arrive at long intervals. It cannot make mining easier until it completes 2,016 blocks at that pace. The monitor puts that at 350 days away, against 14 days for bitcoin.
Support was never there. Only 2.53% of blocks signaled for BIP-110 over the past two weeks, against the 55% needed to activate it without a split.