Generally speaking you are right. To continue with a house payment that is 40-50% of your net income is a tough tough thing to do. But, if you're on a track to make more money within the next 2 years or you have a spouse who is going to be working full time in a couple years, sometimes you have to bite the bullet in order to get into a house while you can still afford its price. It takes INCREDIBLE frugality and patience to do this, and if something bad happens (loss of job, costly illness, etc.) you could really be in a hole quickly.
Just some points though:
1) 40-50% is much less doable with a car payment and student loans and credit card debt. That's why I recommended getting the car payment and the credit card debt gone BEFORE buying a house. Plan to drive that car for 10 more years after it's paid for.
2) No one needs to have cable (I don't, and I make MUCH more than $48,000 per year). No one needs to eat out at $40 a pop. I rarely eat out, and when the family does do it, the four of us usually do so for about $35 tip included. Once a year on our anniversary my wife and I head out to a nice place for dinner, but our frugalness during the year allows us to do that.
3) 40-50% of take home income for a house payment for a couple years is not a big deal. It can be done. If you're in a dead end job and see no ability to make more money, then don't do it.
4) You have to really want that house and make the sacrifices to do it. If the opportunity to buy a house in the neighborhood of your choice comes up and you need to pay 40-50% of your monthly income to do it AND you are financially responsible, you can make it work. In my case, it would have been worse to wait because at the time the houses in my neighborhood were going up 7% a year. Two years of being very tight with the money and now it has loosened up.
Just depends on who you are. My free-spending brother could NEVER make that work. I could though, and did. A home buyer has to be honest with himself about what kind of person he is.