In many cases it is because people are irresponsible, but in some it isn't. A couple of years ago I worked as a loan processor. I didn't determine the rate or term, but I contacted the people and, if they accepted the loan and I could establish they qualified, I'd put through the paperwork to the bank. I spent too much time helping people. Anyway, a few people had 6 figure incomes and lousy credit, but others had gone through some hard times because of illness, divorce, loss of a job and other reasons beyond their control.
"I am so tired of having to come up with something to respond to that"
I do understand you, because I sometimes have the same complaint. I was working in a furniture store and people with no money or credit would walk in and I'd spend an hour with them putting together a furniture package. 90% paid cash or used a credit card, but we also offered credit. When I sent in the application, sometimes it would come back declined & showed that these people had already been to 2 other stores that weekend, so they knew they'd be turned down, but maybe hoped for some really strange reason our lender wouldn't find out??? (I have no idea!) Since I bought my stuff at an auction and went to thrift shops and garage sales, I had no pity for them to be perfectly honest. I sat on a bean bag for a year before I could afford a couch! These young married couples would come in and want to spend $10,000 on a livingroom & bedroom set when they were up to their eyeballs in debt. They were working people with good incomes too.
But then there were those who had very little and weren't aware of the prices until they walked in, so I'd write down the names of less expensive stores where they had damaged or used goods. I once sent someone to Goodwill and got a thank you card they sent to my manager praising me for caring so much since I didn't have anything in their price range. I had seen a nice mattress there for only $60 and explained how they could sterilize it.
So, yes, tntea, I've talked to people who go out and buy expensive televisions & new clothes and then complain when the electricity is shut off for non-payment. However, not everyone is like that. I am not sure what it is that you do for a living (you must have 3 jobs..teacher, convenient store, car dealer... or you teach on a car lot that sells lottery tickets. lol) but it's none of my business, especially with all the jobs I've had! However, I've worked at both new & used car dealerships so I can tell you how to respond.
Any good salesperson knows that being polite and courteous and never passing judgment by the way someone looks or speaks is the only way to treat people of all backgrounds. So my response to "My credit stinks" might be "why don't you come in and sit down and I'll see what I can do for you. We have many different programs and, although I can't promise you'll qualify for one, I'll do my best to find you something that works. If it doesn't, the only thing you've lost is a little time."