Undoubtedly many of your points are right and helping entrepreneurs face the realities of the startup world must surely add value.
However, offering a slightly more positive spin would do little harm and may possibly encourage those aspiring founders out there. Designing, developing and marketing an app is hard but actually that is the case for almost any new business. But it can be done and there are plenty of success stories, even if they are outweighed by the “failures” which themselves can be great learning experiences. In fact, failing at developing an app, is probably one of the fastest ways to learn about entrepreneurship!
There is also plenty of useful advice on some good sites (sure, you need to decipher the good from the bad), some amazing tools that will help you, exceptional training courses (check out Google’s app development stuff) and some really experienced people who are willing to lend a hand if you are prepared to track them down.
My advice, heed Keith’s warning but go ahead and do it anyway. The experience will be invaluable and may well set you on the track to a life of entrepreneurship — which is probably more exciting and rewarding than being a drone in a bank!