The limit increase permits a much healthier outcome for the Bitcoin network and ecosystem.
Today is the limit increase, what will be tomorrow? Are people really wanting to go all in and bet all the todays consensus on the hard-fork? If you read Gavin post about the need for hard-fork, its a totally fear-based move with arguments Bitcoin will be replaced by Altcoins, this means its a matter of time until another need for a hard-fork happen and next time it wont be as trivial need as just increase block-size. I predict next hard-fork will want to increase the number of coins.
So no arguments against, just anti-fork by the rule? If I'm not mistaken, bitcoin has already been forked twice (2013 and 2010?). Are you sure you're on the very first fork?
The last fork was needed the old chain had a really bad bug so bad that no one wanted to use it and it died. This time both chains would be functional.