I'm not sure. Even though it is, as you say, remarkably unsophisticated on a technical level, it is extremely accomplished on a artistic level.
When I first learned about Lenny, I listened to most of his conversations, and it's impressive to hear how often he actually seems to be answering questions or gets distracted in just the right way at just the right time.
The writing (and acting) is just about perfect. I don't know if this is because of sheer genius, or simply lightning in a bottle, but either way I doubt it could be simply reproduced hundreds of times.
I remember first seeing it a while ago, posted here, ironically (or perhaps naturally) in a thread about Spamnasty (also excellent).