I would suspect that the work dried up in the area he lives, and being unwilling to move to find work, he just accepted the "no jobs for me" mantra and started sponging.
Not everyone has the motivation or determination to do something on their own though, so whilst he could have taken to writing software and trying to sell it, he obviously isnt that way inclined.
Which leaves the "lazy waste of space" seeming to be rather apt.