I don't watch them, I don't watch the ones about wannabe celebrities such as the Kardashians, and I don't watch the ones that purport to be competitions, The Apprentice etc. I don't even watch the DIY or gardening ones.
I don't for one minute believe they are real, they are mainly staged and scripted and then cut to get the finish required.
A few years ago I worked with someone who's spouse was involved with a well known show where houses were refurbished in a very short time.
These refurbishments were actually filmed over a week, none of the work was actually achieved in the time claimed.