What?!? What Europe are YOU hiking in, Roger? I just spent two years living on the outskirts of the Pfalzerwald, one of the bigger 'National Parks' in Germany, and it was essentially illegal to camp in it! You had to either:
1. Belong to a trekking club, and use their leased-in-perpetuity gazeebo.
2. Find one such gazeebo, correctly guess which local town had the trekking club it belonged to, call the burgermeister of that town to get the phone number of the club president, call him, PRAY he liked you and would grant you permission to camp at the gazeebo without charging you 100 Euro, etc.
3. Camp in a town fairgrounds. A viable if not very esthetic option, as all of these parks contain towns and farm fields, and are crisscrossed by autobahns.
4. Commando camp, and PRAY a forestmeister didn't find you, because he would cuss you out while speed-dialing the Polizei.
5. Rent a space at a commercial campground- which is actually more expensive than getting a room in a gasthaus for the night, and which is designed for campers with caravans, not tents.
It's like this is most "parks" in Germany. (Yes, scare quotes.) I generally got the impression that while many Germans like to walk, not so many like to HIKE, and a vanishingly small number like to CAMP (the way I use the word, at least).
After all, they cram 85 million people into a country the size of Oregon. If any significant percentage of them were hikers the Alps would be absolutely overrun every weekend. Which, in some ways, it is anyway.
Speaking of which- like all other nations bordering the Alps there are some decent areas in the mountains, though. Even then, in most places generally you HAVE to stay in a hut or other shelter- you can't pitch a tent unless the shelter is full. And even then you must pitch it near the shelter.
Not, mind you, that some jaegerschnitzel and a decent hefeweizen aren't appreciated after the hike to the hut...
What the German's call "National Parks", is more like what an American would call "National Forest." They are managed, and logged.
I'll take the permits, personally. US parks have permits because we are unwilling to pave and build huts everywhere. :o)
Unfortunately, we criminally underfund the NPS.
But, of course, we have our Wildernesses, which IMHO are superior to the Parks.
I will admit that the UK, however, has very enlightened right-of-way laws. Germany does, too, regarding walking over other people's property, but certainly NOT camping there. The Polizei show up QUICK, and accuse you of being gypsies and squatters. Most of Europe actually seems to be tolerant, for instance, of people walking on dirt access roads through a farmer's property- as long as you don't trample a field that's in crop.
I am quite ignorant of Oz. But 20 million people with a whole continent to themselves sounds like Eden. Why do you ever leave, Roger? :o)