The problem with many people is lack of discipline and no long term thinking skills.
+1. I've lost count of how many people I've known over the years who made roughly the $$ I made, lived beyond their means on credit cards and big purchases, and ended up losing their butts (and homes, in some cases). It's crazy. A little self discipline never hurt anybody that I'm aware of.
+2 - People see my house and make snide comments about how nice it must be to be loaded, even though we're making the same kind of money. Meanwhile, they're driving a new BMW every 2 years, paying craploads of credit card debt, living in an overpriced apartment, etc. Here I am driving an 11-year old pickup, and have the house I do because I'm not stupid with my money and was able to pounce when the real estate bubble popped.