Well it depends on what apps; these are not brilliant examples of app and app economy. There are people making that kind of money you are talking about with games like this (4 pics 1 song is top free in the Appstore for instance at the moment and that is known to make quite a bit of cash), but the things you don't see 'in the Appstore' are apps which save companies money, for instance, by optimizing their internal HR or support workflow. Or for instance an app helping chronically ill elderly managing their meds so the on call nurses and doctors have a significant % less workload thus saving money and lives.

These apps will not be in the store, but they are making or saving companies millions. These kind of apps are already critical to a lot of enterprises and are a real opportunity for developers to make your $100k/year and much more.

The promising factor can be in games, but then rather games people stay engaged with (Minecraft, Plague, Plants vs Zombies; not saying if they are good or bad; saying they are liked for years in a row because they are better gameplay and polish wise). Next to that the aforementioned apps either to save or make money; mobile, unlike laptops/desktops, brings apps to everyone, all the time and there is a lot of money to be made in all market segments because of that difference. Both for devs as well as companies hiring these devs.

Oh and, this is definitely a matter of taste, but I rather make $2k/month from home than $10k/month in some gov job in an office. Where I live, you are allowed to work from home in some of those jobs, but they do expect you to be in the office at least 2 days/week and that is definitely something I wouldn't do very unless there is really no other way out.

But I value my work at $50,000/h, so I need to focus on my startup 100%, that's why I didn't want to spend more than 10 days in sustaining myself (10 apps a 24h).