Yes, I really think that's the case. It's actually very difficult to design a puzzle that is challenging yet solvable. One has to take great care to ensure the solution is achievable without the benefit of having the solution to begin with.

With mistakes being made in previous puzzles, I think it's clear that the author is not very rigorous in their design. Further, at the time this puzzle was made it was worth a lot less, so there was much less incentive to do it properly. The fact that the prize money was once worth $100K USD is also a good indication that this may be unsolvable. Look at all the crazy solutions to other ARG's that are worth only a couple hundred bucks. You could imagine those solvers, as well as many more would be attracted to the larger prize of this puzzle. Lots of very brilliant people have worked on this and still nobody has even a confirmed first step.

From the authors perspective I'm sure it seems simple, but to those without the benefit of knowing the solution, it might not be solvable. This is basically the definition of hindsight bias.