Minus one point for doubling up on Malcolm in the Middle. Plus 10 points for referencing Spaced, which I hope you all have seen.
That's why, precisely. Because comic book fans feed the stereotype, at least partly as self-deprecation. The other part is just being oblivious to how we fit it.
In some cases, as with Ridley Scott's sci-fi classic Blade Runner, the adaptations are loose to say the least.
Given the nature of most of Dick's work, a direct 1:1 film adaptation of his writing would be at best nonsensical. Adapting the theme of the work, and leaving leeway with the details is generally the best approach.
Hell, even with other author's works it's the best approach. They are completely different media after all, and require completely different approaches to storytelling.
The first version always gets thrown away.