I don't know how much of your £5 a month goes to SI, but it'll be pennies, if that. The rest is spread between the developers of the hundreds of other games you get access to. No one is forcing you to subscribe, and FM is still available on other platforms as normal.
It wasn't financially viable to release the game on iPad for purchase (as they'd done for years), or SI would have kept doing it. The only way to make it viable was clearly to sign a deal with Apple to bring it to Arcade. You now have an OPTION to get Touch on the iPad (plus iPhone, Apple TV and even Mac) which you wouldn't have had otherwise. If you don't want to pay the £5 p/m, you're no worse off than you were last year.