I think there's a strong argument that it wasn't just that the compiler technology was insufficiently god-like but also that they over-estimated the degree to which instruction-level parallelism mattered to the general market. The quote below really fits my memory of the initial experience — the claims were really ambitious but even if it'd on-time (i.e. 2+ years earlier) and at the originally promised clock rates the results wouldn't have been especially impressive outside of a few fields like scientific computing. Even in HPC it was a question of how much time you were willing to spend hand-tuning every hot section. When it finally did ship, we got access to a dev system and found the Itanium systems generally struggled to surpass the previous generation systems which we were preparing to replace.

“Davidson also pointed out two areas where academic research could create a blind spot for architecture developers. First, most contemporary academic research ignored CISC architectures, in part due to the appeal of RISC as an architecture that could be taught in a semester-long course. Since graduate students feed the research pipeline, their initial areas of learning frequently define the future research agenda, which remained focused on RISC. Second, VLIW research tended to be driven by instruction traces generated from scientific or numerical applications. These traces are different in two key ways from the average system-wide non-scientific trace: the numerical traces often have more consistent sequential memory access patterns, and the numerical traces often reflect a greater degree of instruction-level parallelism (ILP). Assuming these traces were typical could lead architecture designers to optimize for cases found more rarely in commercial computing workloads. Fred Weber echoed this latter point in a phone interview. Bhandarkar also speculated that the decision to pursue VLIW was driven by the prejudices of a few researchers, rather than by sound technical analysis.”

The rest of this PDF is well worth reading:

http://courses.cs.washington.edu/courses/csep590/06au/projec...