I think it depends on your income. If you are making a relatively small amount of money per month and want to have a decent lifestyle, you can't go out and have 50% of your income be for your mortgaeg payment, because the remainder may not be enough to get you through the month.
However, if you make a relatively large amount of money, you could afford to spend more of your monthly income on a house alone, because the remainder would be able to maintain you at a reaosnable lifestyle depsite the high payment.
E.g., if you NET 2 grand per month, and spend $1000 on a mortgage, that leaves $1000 bucks for everything else that month, gas, food, insurance, diapers, etc... Thats not a lot in this day and age.
If you NET 8 grand in a month, however, you could spend 50% on your mortgage and be left with 4 grand for the remainder of the month to pay for other crap. As long as you don't go crazy with everything you do, you could still have the big expensive house and be fine.
Personally, I think owning a house where the payment was much more than 25% of my NET income per month would be too much. Of course, other people have different comfort levels. I would just rather have a smaller house with some nice stuff in it than an unfurnished castle.