Or you could just change your route. Or you could walk your bike through the park and enjoy it a little more slowly.
Because there is a rule, people who see you breaking it will get pissed off. It’s just the same as a driver sitting at a red light getting pissed off watching a cyclist run the red. Cyclists struggle to get respect from a lot of people. Little things like this add up. And those people may or may not be irrational in their anger. But do you really need to piss them off?
If you don’t like the rule why don’t you contact the local Council and say something about it? And if you feel you are justified in riding slowly and safely through the park, then why don’t you say to the Council that the rule should be altered to allow slow safe cycling? The Council might have something to say in response, and there may even be some rational counter-arguments you are not aware of for why it is a good idea to stop cycling in this one park.