We don't know how much this dude made from websites either. I've repeated it several times, but 'making websites' can make you a ton of money if you know what you're doing. Look up salaries for Ruby on Rail developers or front-end developers and see for yourself.
Given his lifestyle, he very well could have been self-sufficient, especially given his frugal habits, while stashing away his oil checks. People are calling him a bum, but at least he's living within his means if that's the case. If you have no car note and minimize your expenditures on things such as the latest clothes and gadgets, you can save a ton of money.
If she felt that he was unambitious and a bum and wanted better for herself, that's fine... but don't change your tune when you learn of his inheritance because he's still that so-called unambitious bum. In that case, it's not about 'ambition'... it's about how much money he has to spend on you.
Money means different things to different people. For a lot of people, it's a means to purchase materials, whether it be clothes, cars, etc. For others it's a means to control your time and not have to punch a clock and to be able to spend your time how you see fit. A lot of people would seem unambitious if they had say $9,000 coming in every month which they were free to do as they saw fit with... why? Because they'd be living life how the wanted as opposed to punching the clock at some job they hate.
She's not wrong for leaving. She's wrong for slandering this dude, but trying to run back once she learned he had cash. He was this super cheapskate, but she enjoyed dating him until she saw what her 'girls' supposedly had... and then the current deal wasn't enough. He's this lazy bum, so why does she want to go back? Can anyone tell me how having an inheritance magically changes all of these supposed flaws in characters, which were flaws she saw as perfectly acceptable until she started looking on facebook and judging what she had based upon what she perceives her friends to be doing?