I used the unpaid example to draw a sharper contrast. A large block of time off is generally unavailable under any terms, except at companies like FB (or apparently everywhere in Europe) that explicitly call out child-rearing.
Since you seem to know of the system: If European democracies have a state system for paying for the leave, did the debate include proposals to allow payments for other avocations?
Europe is a big place and it probably varies to jurisdiction to jurisdiction, but I'd say generally no. I know that here in Norway there are a few other exceptions where the government may step in and pay like if you're giving care to someone seriously ill because you're a de facto replacement for public healthcare but for personal projects you are on your own. It has been suggested though that those who want to be slackers can be employed for a relatively short while, then go on unemployment benefits while making crap applications for jobs they won't get, flunk interviews and in general be unemployable while formally meeting the requirements. For the more serious people though I know some that have gotten 6-12 months unpaid leave to pursue some personal dream in the private sector, in the public sector it's even easier.
I think this very much relates to the use of overtime and wage politics, in Europe you generally have to pay for every hour and to be honest you're usually paying overpaying unskilled/untrained people and underpaying your best people. Which means that if good employees don't get their leave and instead quit thinking their CV is good enough to get re-employed a year later you as an employer lose. They have to deal with similar leaves quite often for the 50% that's female and we also have a shorter paternity leave, so really there's no reason to be a dick about it. I guess it depends on why though, if you're starting a competing business then no.... the one I know who got a 12 month leave sailed around the world. Pretty bold move, but it was also fairly certain he'd be coming back. I think it takes a large company though, the smaller the harder it'll be.