A missed plot point
This is probably my favorite Kevin Smith film after Clerks. But I noticed something while watching it this time around - If Zack was serious about getting into porn, why didn't he just get in touch with Brandon and Bobby Long? It's what meeting Brandon that inspires Zack to do a porno, but since they are scrapped for cash but had a couple of great ideas, he could have easily gotten in touch with Brandon and asked how to go about getting into the business and marketing their film. At the end, we see that the characters return and are shooting a movie under Zack and Miri's own company.
Now days I get that they could have just uploaded it online to various porn sites, but if they were serious about getting into the business, I'm surprised at most this is an idea he never even speculated. Especially after their first studio gets destroyed and they lose everything they worked on.
I guess the most simple explanation is that they wanted to be totally independent, it just seems like that is a strong connection that they never even considered (as characters, I mean. I'm sure it occurred to Kevin while writing it.)