alt Hacker News15 days is the duration for visa-free entry available to the citizens of the 54 "Western" countries. Only Singapore nationals get more than that.
The validity of a tourist visa is 90 days - it doesn't mean that presenting a 90 day itinerary is accepted upon application with a Chinese consular office. And as a general rule, it's not. If yiur itinerary includes any destinations outside approved areas, certainly not. As for hotels, see the following thread: https://www.reddit.com/r/China/comments/17fe0p9/why_do_lots_.... The vast majority of hotels will not accept your booking.
With all due respect, I don't think you know what you're talking about. =)
My personal experience as a Western tourist is that I could travel all around China for 2 months with no real issues. The provided itinerary was mostly a formality (and I didn't have to stick to it strictly). I managed to book hotels, trains, I even got a permit to go to Tibet (although a guide was required for that portion of the trip). It's true not all hotels can host foreigners, but in practice that's rarely a problem.
Although I personally wouldn't live there long term, China has actually a lot to offer as a tourist destination. It's very safe and there's lots of interesting history and beautiful nature to explore. It can obviously be challenging to move around without speaking the language, but some spirit of adventure goes a long way.