Leethul
It's not so much "messy" as you put it, but more a case of doing the right thing by all beach users, so that kiters can maintain access to our favourite spots.
Some of the sentiment behind the guidelines cards that have been developed (distributed at retailers & online here on SB) is to assist kiters from out of town (yep, that's you buddy....

- but also for our Teuro friends) who might not know the local do's and don't's - rather than can & cannot as you suggested.
We have a rough estimate of about 2500 kiters in WA, far far in excess of the numbers in Tassie. You're pretty lucky to have minimal numbers, fewer hassles & far fewer problems to deal with. As the sport grows here, incidents and issues will become more frequent - the guidelines are an attempt, one way to hopefully minimise incidents and issues.
The guidelines are our suggestions and guidelines to minimise issues; maintain access & keep everyone on the beach happy. The guidelines are only that - guidelines - but, depending on where you kite, you will find them fairly rigidly enforced especially say @ Mullaloo - fail to comply with the guidelines at Mullaloo & it's safe to say someone will be in your ear pretty quickly.
Welcome to Perth, hope you have a great time and we hope you find the guidelines useful and contribute to you having a more enjoyable kite at any of our great beaches.