One thing leaves me puzzled though. How was Ali able to afford his addiction and party life style for so very long?
It's one thing when, say, Spanky gets his checks cut because he isn't skating on a level deemed worthy of someone getting paid to, realistically, not have a job and most real life responsibilities. However, Ali's shtick was that he was a pile that could sometimes skate exceedingly well. Watch any of his parts and there is a good amount of none-skate footy to pad it out. It wa as if Flip or whomever was saying "Look at this guy! He's a fucking nut! He doesn't need to actually film a full part's worth of shit, the kids will eat this shit up any way! Look at him spreading his ass cheeks, that could have been a trick, but nah, he doesn't need to!".
Basically, what I'm trying to get at is that his downward spiral may have either been ignored/overlooked because he was still producing enough to get by, or that it was ignored/overlooked because it was part of what made him so marketable to kids at that time. Jackass/Bam was popular, and once kids grew out of that and saw Ali doing the same sort of sus shit, they latched onto him. Him being nuts and a pile is what made him popular, so why would they decide to cut the pay on a cash cow? Same reason they didn't take Penny's board away while he was on his sabbatical... he was making them money, and it was his shtick.
Also, look at, say, homeless drug addicts... that's another situation where you have to wonder 'How did you even get the money to get Substance X?' It doesn't matter, they got the money to procure it somehow, even if it means doing something super suspect for it.