I think you'll find the 'it will definitely collapse' brigade are as clueless as anyone else vulgar. I'm unsure why you find them dangerous, just practical.
I think there will be a crash; however I do not know if, or when it will be. I'm certainly not a housepricecrasher - who I think have been foolish; they've wasted 10 or more years bring scared and waiting for a bargain when there is a 'crash' rather than using that time to pay a mortgage halfway down.
There is a lot of info out there for research purposes and you can make your own mind up.
I worry because we have a humongous mortgage; in 2008 we were totally unprepared for the credit crunch and really struggled because Dh lost his job, and I've spent the last 7 years getting our debt down to try and withstand another downturn should it happen.
It was scary, and I want to be prepared for the next one if it happens.